Tuning the Ionic and Dielectric Properties of Electrospun Nanocomposite Fiber...IJERA Editor
This study reports the fabrication and characterization of electrospun polyvinylidene fluoride (PVdF)and
polyvinylpyrrolidone (PVP) nanofiber separators embedded with carbon black nanoparticles. Different weight
percentages (0, 0.25, 0.5, 1, 2, and 4wt%) of carbon black nanoparticles were dispersed in N, Ndimethylacetamide
(DMAC) and ethanol using sonication and high-speed agitations, and then PVdF and PVP
polymers were added to the dispersions prior to the mixing and electrospinning processes. The morphological,
dielectric constant, ionic conductivity, and surface hydrophobic properties of the PVdF/PVP nanofiber
separators were analyzed using various techniques. SEM micrograms showed that the fiber diameter was
around 100-200 nm. The ionic conductivity test clearly revealed a significant increase in conductivity valueof
4.28 x 10-4
S/cm for 4 wt. % carbon black loading. However, the contact angle values were decreased with
increasing weight percent of carbon black particles. The dielectric constant was increased with the carbon black
loading. As can be seen, overall physical properties of the nanocomposite separators were significantly
enhanced as a function of carbon black inclusions, which may be useful for supercapacitor separators and other
energy storage devices
Tuning the Ionic and Dielectric Properties of Electrospun Nanocomposite Fiber...IJERA Editor
This study reports the fabrication and characterization of electrospun polyvinylidene fluoride (PVdF)and
polyvinylpyrrolidone (PVP) nanofiber separators embedded with carbon black nanoparticles. Different weight
percentages (0, 0.25, 0.5, 1, 2, and 4wt%) of carbon black nanoparticles were dispersed in N, Ndimethylacetamide
(DMAC) and ethanol using sonication and high-speed agitations, and then PVdF and PVP
polymers were added to the dispersions prior to the mixing and electrospinning processes. The morphological,
dielectric constant, ionic conductivity, and surface hydrophobic properties of the PVdF/PVP nanofiber
separators were analyzed using various techniques. SEM micrograms showed that the fiber diameter was
around 100-200 nm. The ionic conductivity test clearly revealed a significant increase in conductivity valueof
4.28 x 10-4
S/cm for 4 wt. % carbon black loading. However, the contact angle values were decreased with
increasing weight percent of carbon black particles. The dielectric constant was increased with the carbon black
loading. As can be seen, overall physical properties of the nanocomposite separators were significantly
enhanced as a function of carbon black inclusions, which may be useful for supercapacitor separators and other
energy storage devices
One-Dimensional Carbon Nanostructures—From Synthesis to Nano-electromechanica...Mariana Amorim Fraga
The fundamental properties of one-dimensional (1D) carbon nanostructures and their promising technological applications have stimulated significant research in different areas. Because of their outstanding electrical and mechanical properties, these nanostructures have emerged as a new class of sensor material with real potential for a variety of nano-electromechanical systems (NEMS). Several studies have shown that the performance of a NEMS device is significantly affected by the material properties of the nanostructures used to build it. For this reason, a section of this review is devoted to the synthesis and properties of 1D carbon nanostructures including nanotubes, nanofibers, and nanowires. Thereafter, some NEMS-based sensors using 1D carbon nanostructures are introduced and issues related to their fabrication processes are addressed. The goal of this brief review is to outline the benefits of the use of 1D carbon nanostructures, the current status of development and challenges to enable their widespread application as sensing elements in NEMS devices.
pp. 39-56
S&M1299
http://dx.doi.org/10.18494/SAM.2017.1366
Online Published: January 25, 2017
Quantum dots for optoelectronic devices - phdassistancePhD Assistance
Nanometre-scale semiconductor chips have been imagined as next-generation technology with high functionality and convergence. Quantum dots, also known as artificial atoms, have special properties owing to their quantum confinement in all three dimensions. Quantum dots have a lot of interest in optoelectronic systems because of their special properties.
For decades, self-assembled nanostructures have been a topic of considerable concern and significance.
Learn More:https://bit.ly/3xJJAiZ
Contact Us:
Website: https://www.phdassistance.com/
UK: +44 7537144372
India No:+91-9176966446
Email: info@phdassistance.com
PolyMEMS INAOE, a Surface Micromachining Fabrication Module and the Developm...José Andrés Alanís Navarro
The PolyMEMS INAOE module for surface micromachining has been developed for the fabrication of electrostatic and electrothermal (Joule effect) sensors and actuators. In this module the designer can choose up to 3 Poly silicon layers and aluminum as electrical interconnecting material. A
micromechanical test chip has been fabricated which includes the following. a) Micro test structures for residual stress measurement; cantilever beams, clamped-clamped beams, ring-and-beam structures, diamond-and-beam structures, rotation beams, Vernier gauges, cantilever spirals, double-clamped microgauge, and b) Actuators; torsion and bending mirrors, resonators, single two-arms Joule structures (STA), chevron-like Joule arrays, capacitive array for accelerometers. In this work we are presenting the measured residual stress on our process, by using the clamped-clamped beam and ring-and-beam arrays. The measured compressive stress is in the 21-26 MPa range for both types of microgauges. A maximum typical value for this tensile stress is 50 MPa, which is higher than that obtained in our experimental procedure. From this residual stress measurement technique and other mechanical testing routines we can conclude the following: the thermal load, the polysilicon microstructure, and the releasing technique; all of them result in a reliable process for the fabrication of dynamic and static polysilicon microstructures.
SIMULATION OF THE SOLAR CELLS WITH PC1D, APPLICATION TO CELLS BASED ON SILICONAEIJjournal2
A way of exploiting the solar energy is to use cells photovoltaic which convert the energy conveyed by the incidental radiation in a continuous electric current. This conversation is based on the photovoltaic effect engendered by the absorption of photons. A part of the absorbed photons generates pairs electron-hole in which an electric field created in the zone of load of space of a junction p–n. Thus, the junction p-n, its characteristics, its components and its dimensions are the parameters responsible of the efficiency and the performances of a solar cell. To study this, we are going to use a very known software in the mode of the simulation of solar cells, the PC1D, and we are going, at the end, to draw a conclusion around the ideal parameters that a good solar cell has to have.
Los días 22 y 23 de junio de 2016 organizamos en la Fundación Ramón Areces un simposio internacional sobre 'Materiales bidimensionales: explorando los límites de la física y la ingeniería'. En colaboración con el Massachusetts Institute of Technology (MIT), científicos de este prestigioso centro de investigación mostraron las propiedades únicas de materiales como el grafeno, de solo un átomo de espesor, y al mismo tiempo más resistente que el acero y mucho más ligero.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
One-Dimensional Carbon Nanostructures—From Synthesis to Nano-electromechanica...Mariana Amorim Fraga
The fundamental properties of one-dimensional (1D) carbon nanostructures and their promising technological applications have stimulated significant research in different areas. Because of their outstanding electrical and mechanical properties, these nanostructures have emerged as a new class of sensor material with real potential for a variety of nano-electromechanical systems (NEMS). Several studies have shown that the performance of a NEMS device is significantly affected by the material properties of the nanostructures used to build it. For this reason, a section of this review is devoted to the synthesis and properties of 1D carbon nanostructures including nanotubes, nanofibers, and nanowires. Thereafter, some NEMS-based sensors using 1D carbon nanostructures are introduced and issues related to their fabrication processes are addressed. The goal of this brief review is to outline the benefits of the use of 1D carbon nanostructures, the current status of development and challenges to enable their widespread application as sensing elements in NEMS devices.
pp. 39-56
S&M1299
http://dx.doi.org/10.18494/SAM.2017.1366
Online Published: January 25, 2017
Quantum dots for optoelectronic devices - phdassistancePhD Assistance
Nanometre-scale semiconductor chips have been imagined as next-generation technology with high functionality and convergence. Quantum dots, also known as artificial atoms, have special properties owing to their quantum confinement in all three dimensions. Quantum dots have a lot of interest in optoelectronic systems because of their special properties.
For decades, self-assembled nanostructures have been a topic of considerable concern and significance.
Learn More:https://bit.ly/3xJJAiZ
Contact Us:
Website: https://www.phdassistance.com/
UK: +44 7537144372
India No:+91-9176966446
Email: info@phdassistance.com
PolyMEMS INAOE, a Surface Micromachining Fabrication Module and the Developm...José Andrés Alanís Navarro
The PolyMEMS INAOE module for surface micromachining has been developed for the fabrication of electrostatic and electrothermal (Joule effect) sensors and actuators. In this module the designer can choose up to 3 Poly silicon layers and aluminum as electrical interconnecting material. A
micromechanical test chip has been fabricated which includes the following. a) Micro test structures for residual stress measurement; cantilever beams, clamped-clamped beams, ring-and-beam structures, diamond-and-beam structures, rotation beams, Vernier gauges, cantilever spirals, double-clamped microgauge, and b) Actuators; torsion and bending mirrors, resonators, single two-arms Joule structures (STA), chevron-like Joule arrays, capacitive array for accelerometers. In this work we are presenting the measured residual stress on our process, by using the clamped-clamped beam and ring-and-beam arrays. The measured compressive stress is in the 21-26 MPa range for both types of microgauges. A maximum typical value for this tensile stress is 50 MPa, which is higher than that obtained in our experimental procedure. From this residual stress measurement technique and other mechanical testing routines we can conclude the following: the thermal load, the polysilicon microstructure, and the releasing technique; all of them result in a reliable process for the fabrication of dynamic and static polysilicon microstructures.
SIMULATION OF THE SOLAR CELLS WITH PC1D, APPLICATION TO CELLS BASED ON SILICONAEIJjournal2
A way of exploiting the solar energy is to use cells photovoltaic which convert the energy conveyed by the incidental radiation in a continuous electric current. This conversation is based on the photovoltaic effect engendered by the absorption of photons. A part of the absorbed photons generates pairs electron-hole in which an electric field created in the zone of load of space of a junction p–n. Thus, the junction p-n, its characteristics, its components and its dimensions are the parameters responsible of the efficiency and the performances of a solar cell. To study this, we are going to use a very known software in the mode of the simulation of solar cells, the PC1D, and we are going, at the end, to draw a conclusion around the ideal parameters that a good solar cell has to have.
Los días 22 y 23 de junio de 2016 organizamos en la Fundación Ramón Areces un simposio internacional sobre 'Materiales bidimensionales: explorando los límites de la física y la ingeniería'. En colaboración con el Massachusetts Institute of Technology (MIT), científicos de este prestigioso centro de investigación mostraron las propiedades únicas de materiales como el grafeno, de solo un átomo de espesor, y al mismo tiempo más resistente que el acero y mucho más ligero.
International Journal of Engineering Research and Applications (IJERA) is an open access online peer reviewed international journal that publishes research and review articles in the fields of Computer Science, Neural Networks, Electrical Engineering, Software Engineering, Information Technology, Mechanical Engineering, Chemical Engineering, Plastic Engineering, Food Technology, Textile Engineering, Nano Technology & science, Power Electronics, Electronics & Communication Engineering, Computational mathematics, Image processing, Civil Engineering, Structural Engineering, Environmental Engineering, VLSI Testing & Low Power VLSI Design etc.
The preparation of thin zinc air battery. The cell, 1 cm2 area x ca. 460 μm thick, possesses limiting current of 27 mA, maximum power output of 31 mW, and vlumetric energy
density of 924 Wh l-1, rated at 20 mA. A bipolar design
markedly improves the cell performance. The cell, 1 cm2
area x ca. 920 μm thick, possesses limiting current
of 95 mA, maximum power output of 107 mW, and
volumetric energy density of 1189 Wh l-1.
A new miniaturized wideband self-isolated two-port MIMO antenna for 5G millim...TELKOMNIKA JOURNAL
Nowadays, millimeter-wave frequencies present a catchy solution to securing the colossal data rate needed for 5G communications. Accordingly, this research deals with the conception of a novel orthogonal 2×2 multiple input, multiple output (MIMO) antenna design operating in the millimeter wave spectrum with quite small dimensions of 11×6×0.8 mm3. The single antenna element consists of a trapezoidal microstrip patch antenna built on the Rogers RT5880 laminate with a permittivity of 2.2 and tangent loss of 0.0009. A trapezoidal-slot ground plane is used to support the structure. The antenna resonates at 28 GHz with a large bandwidth of 4 GHz from 26 to 30 GHz, a good gain of up to 5 dB, and a high radiation efficiency of 99%. A strong isolation is achieved that surpasses 26 dB. Besides, a high diversity performance is achieved where the envelope correlation coefficient (ECC) is lower than 0.001, the diversity gain (DG) is greater than 10 dB, and the channel capacity loss (CCL) is no longer than 0.4 bit/s/Hz. The achieved outcomes prove the robustness of the suggested MIMO antenna and qualify it to be a strong candidate for 5G wireless devices.
High Capacity Planar Supercapacitors and Lithium-Ion Batteries byModular Man...Bing Hsieh
High Capacity Planar Supercapacitors and Lithium Ion Batteries by Modular Manufacturing
Novel planar supercapacitors (SC) and lithium ion batteries (LIB) having interdigitated electrodes for large format applications will be presented. We will discuss the design principles of the new planar structures, their potential to give > 5X improvement in capacity over current supercapacitors, their pack designs, as well as low cost fabrication by modular manufacturing. The drawings given in the following link depict the plan view (top) and the cross-sectional view (bottom) of a planar LIB, wherein the dotted and the hatched areas are the positive and the negative electrodes respectively; the gray areas are the current collectors and the gray lines are the grid lines. Unlike the known interdigitated thin film microsupercapacitor design where the current collectors are situated on the top or bottom surfaces of the electrodes and paralleled to the plane of the substrate and can only exert limited weak fringe fields, the current collectors in our new design are running along the sidewalls of the electrodes and are perpendicular to the substrate and can thus provide strong direct fields, as indicated by the purple arrow, to promote facile ion movement across the entire thickness of the electrodes (20-100 µm). In addition, the relatively narrow inter-spaces between two opposite electrodes (20-100 µm) may allow much higher power densities than ever. Due to their scalability and low cost modular manufacturing processes by printing, the new planar SC/LIB may be designed for a wide range of applications such as mobile devices, transportation, and grid and distributed energy storage.
https://drive.google.com/file/d/0B7fDeNQTYRc9VDdOTTVYRmh2QWc/view?usp=sharing
Different Generation Solar Cells
CIGS and CZTS Based Technology
Ink Based Technology
CIGS Device Structure
Making more efficient solar cells
Developing thin film technologies using alternative less costly materials and methods
Incorporate innovative cheaper deposition methods such as electrodeposition and printing technology
Advances on Microwave Ceramic Filters for Wireless Communications (Review Pap...IJECEIAES
A review of the technological developments on ceramic monoblock filters and duplexers over the years is presented in this work. Early designs based on simulated and measured data are presented along with later designs based on accurate equivalent circuits as well as the use of evolution algorithms for optimal design.
International Journal of Engineering Research and Applications (IJERA) is a team of researchers not publication services or private publications running the journals for monetary benefits, we are association of scientists and academia who focus only on supporting authors who want to publish their work. The articles published in our journal can be accessed online, all the articles will be archived for real time access.
Our journal system primarily aims to bring out the research talent and the works done by sciaentists, academia, engineers, practitioners, scholars, post graduate students of engineering and science. This journal aims to cover the scientific research in a broader sense and not publishing a niche area of research facilitating researchers from various verticals to publish their papers. It is also aimed to provide a platform for the researchers to publish in a shorter of time, enabling them to continue further All articles published are freely available to scientific researchers in the Government agencies,educators and the general public. We are taking serious efforts to promote our journal across the globe in various ways, we are sure that our journal will act as a scientific platform for all researchers to publish their works online.
Module PHY6002 Inorganic Semiconductor Nanostructures
Lectures 7, 8, 9 and 10
1
Lecture 7 – The fabrication of semiconductor
nanostructures I
Introduction
In this lecture we will look at the techniques used to fabricate semiconductor
nanostructures. The well-established epitaxial methods used to produce
quantum wells will be described. The main techniques applied to produce
quantum wires and quantum dots will be discussed, with a comparison of their
relative advantages and disadvantages. In the next lecture we will look in
detail at the most successful technique used to produce quantum dots, self-
organisation.
Epitaxial techniques
There are two well established epitaxial growth techniques used to produce
high quality quantum wells: molecular beam epitaxy (MBE) and metal organic
vapour phase epitaxy (MOVPE).
The following figure shows the main components of an MBE reactor.
The reactor consists of an ultra-high vacuum chamber with a number of
effusion cells, each containing a different element. Each cell has a mechanical
shutter placed in front of its opening. In operation the cells are heated to a
temperature where the elements start to evaporate, producing a beam of
atoms which leave the cells. These beams are aimed at a heated substrate
which consists of a thin wafer of a suitable bulk semiconductor. The incident
beams combine at the surface of the substrate and a semiconductor is
deposited atomic-layer by atomic-layer. The substrate is rotated to ensure
even growth over its surface. By opening the mechanical shutters in front of
certain cells it is possible to control which semiconductor is deposited. For
example opening the shutters in front of the Ga and As cells results in the
growth of GaAs. Shutting the Ga cell and opening the Al cell switches to the
growth of AlAs. Because the shutters can be operated very rapidly in
comparison to the rate at which material is deposited, it is possible to grow
An MBE reactor
Module PHY6002 Inorganic Semiconductor Nanostructures
Lectures 7, 8, 9 and 10
2
very thin layers with very sharp interfaces between layers. The following figure
shows a transmission electron microscope image of a quantum well sample
containing five wells of different thicknesses. The thinnest well has a
thickness of only 1nm. Other cells in the MBE reactor may contain elements
used to dope the semiconductor and it is possible to monitor the growth as it
proceeds by observing the electron diffraction pattern produced by the
surface.
The second epitaxial growth technique is metal organic vapour phase epitaxy
(MOVPE). In this technique the required elements are carried, as a
component of gaseous compounds, to a suitable chamber where they mix as
the gases flow over the surface of a heated substrate. The compounds
breakdown to deposit the semiconductor on the surface of the substrate with
the remaining waste gases being removed from the chamber. Valves in the
gas l ...
CIGS Solar Cells: How and Why is their Cost Falling?Jeffrey Funk
My master's students use concepts from my (Jeff Funk) forthcoming book (Technology Change and the Rise of New Industries) to analyze the economic feasibility of CIGS (Cadmium Indium Gallium Selenide) Solar Cells. Improvements in efficiencies and reductions in cost per area (through new processes and increasing the substrate size) are causing steady reductions in the cost of electricity from them. See my other slides for details on concepts, methodology, and other new industries..
The Evolution Of An Electronic Materialdavekellerman
This presentation displays a development effort that took several years. The achieved goal was attained: a complete materials system that may be used to fabricate substrates for high speed and microwave single and multichip semiconductor substrates and packages
Similar to NIMA 57184 Pilot production & commercialization of LAPPD™ Published Copy 05-08-2015 (20)
NIMA 57184 Pilot production & commercialization of LAPPD™ Published Copy 05-08-2015
1. Pilot production & commercialization of LAPPD™
Michael J. Minot a,n
, Daniel C. Bennis a
, Justin L. Bond a
, Christopher A. Craven a
,
Aileen O'Mahony a
, Joseph M. Renaud a
, Michael E. Stochaj a
, Jeffrey W. Elam b
,
Anil U. Mane b
, Marcellinus W. Demarteau b
, Robert G. Wagner b
, Jason B. McPhate c
,
Oswald Helmut Siegmund c
, Andrey Elagin d
, Henry J. Frisch d
, Richard Northrop d
,
Matthew J. Wetstein d
a
Incom Inc, 294 Southbridge Road, Charlton, MA 01507, USA
b
Argonne National Laboratory, 9700 S. Cass Avenue, Lemont, IL 60439-4814, USA
c
Space Sciences Laboratory, University of California, Berkeley, CA 94720, USA
d
University of Chicago, 5640 S. Ellis Ave., Chicago, IL 60637, USA
a r t i c l e i n f o
Available online 25 November 2014
Keywords:
Large-area picosecond photodetectors
(LAPPD)
Time of flight detector
Glass capillary array (GCA)
Microchannel plate (MCP)
Atomic layer deposition (ALD)
a b s t r a c t
We present a progress update on plans to establish pilot production and commercialization of Large Area
(400 cm2
) Picosecond Photodetector (LAPPD™
). Steps being taken to commercialize this MCP and
LAPPD™
technology and begin tile pilot production are presented including (1) the manufacture of
203 mm  203 mm borosilicate glass capillary arrays (GCAs), (2) optimization of MCP performance and
creation of an ALD coating facility to manufacture MCPs and (3) design, construction and commissioning
of UHV tile integration and sealing facility to produce LAPPDs. Taken together these plans provide a
“pathway toward commercialization”.
& 2014 Elsevier B.V. All rights reserved.
1. LAPPD
The Large Area Picosecond Photodetector (LAPPD™
) is a micro-
channel plate (MCP) based photodetector, capable of imaging, and
having both high spatial and temporal resolution in a vacuum
package with an active area of 400 cm2
. LAPPD™
are characterized
by a uniquely simple design based upon an all-glass vacuum
package comprised of top and bottom plates and square sidewall,
each made of borosilicate float glass, depicted in Fig. 1.
Key design features of the LAPPD include: (a) an internal chevron
pair stack of “next generation” MCPs produced by applying resistive
and emissive coatings to borosilicate glass capillary array (GCA)
substrates; (b) a modular all-glass detector package with conductive
RF microstrips passing through a glass frit seal that hermetically
bonds the side walls to the bottom anode plate while allowing
electrical contact to the interior of the device; eliminating the need
for metal electrical pins penetrating the evacuated detector package;
(c) resistively coated spacers that function as high voltage (HV)
dividers to distribute voltage across the MCP chevron stack, elim-
inating the need for separate electrical leads contacting the tops and
bottoms of both MCPs; and (d) RF stripline anodes applied to the
bottom plate with an analog bandwidth above 1.5 GHz for good
spatial and temporal resolution [1].
1.1. MCP based photodetectors
MCP's consists of millions of conductive glass capillaries (4–25 mm
in diameter) fused together and sliced into a thin plate [2]. Each
capillary or channel works as an independent secondary-electron
multiplier. Single electrons that hit a pore on one side of the plate
convert into large bunches of electrons that cascade from the other
side [3], with typical amplification from a pair of plates of 107
.
Fig. 2 (left) shows a large area glass capillary array (GCA) consisting of
millions of 20 mm diameter pores with an overall size of 203 mm Â
203 mm 1.2 mm with an aspect ratio¼60:1, bias angle of 81, and
open area ratio of 60%. Atomic Layer Deposition (ALD) techniques are
used to apply resistive and emissive coatings, converting the GCA
into a high performance MCP. A high voltage is applied across the top
and bottom surfaces of the MCP; a photocathode applied to the
inside surface of the entrance window emits photo-electrons which
are then accelerated to the microchannel plate structure for fast
multiplication of signals, as depicted in Fig. 2 (right) [4].
MCP-based photodetectors offer many advantages over other
sensors. They are compact, lightweight, have unmatched temporal and
good spatial detection properties, and can provide two-dimensional
imaging with correlated timing at the picosecond level. Despite rapid
Contents lists available at ScienceDirect
journal homepage: www.elsevier.com/locate/nima
Nuclear Instruments and Methods in
Physics Research A
http://dx.doi.org/10.1016/j.nima.2014.11.025
0168-9002/& 2014 Elsevier B.V. All rights reserved.
n
Corresponding author. Tel.: þ1 508 909 2369; fax: þ1 508 765 0041.
E-mail address: mjm@incomusa.com (M.J. Minot).
Nuclear Instruments and Methods in Physics Research A 787 (2015) 78–84
2. progress on various solid state detectors, vacuum based photon
detectors still play a significant role in many high energy experiments
where high speed detection of weak photon signals is critical. One of
the biggest advantages of the vacuum devices over solid state ones is
their fast response. The photo-electron conversion, or QE, is typically
only fair (about 20–35%), but the devices are unmatched for high gain,
low noise, and response time and (for MCP-based devices) space
resolutions.
2. “Next generation” MCPs
An enabling component of the LAPPD™ is a chevron pair of
large area (203 mm  203 mm) “next generation” MCPs. The
manufacture of these “next generation” large-area high perfor-
mance MCPs has been facilitated by the convergence of two
technological breakthroughs.
The first breakthrough is the ability to produce large blocks of
hollow, micron-sized glass capillary arrays (GCAs) developed by
Incom Inc. The Incom process is based on the use of hollow
capillaries in the glass drawing process, eliminating the need to
later remove core material by chemical etching. These substrate
arrays are made using the following steps: (a) a single glass tube is
heated and drawn under tension to form a hollow capillary; (b)
multiple glass capillaries are assembled to form an assembly that is
heated and drawn to form a multi-capillary bundle; (c) multi-
capillary bundles are further assembled and heated under pressure
to form a large fused block; (d) the fused capillary block is sliced as
shown in Fig. 3, and finished into glass capillary array (GCA) wafers
having the desired dimensions.
One benefit of this approach is that GCAs can be made without
regard to the conventional limits of capillary length/diameter (L/d)
ratios. Moreover, borosilicate glass (Pyrexs
or similar) is consider-
ably less expensive than the leaded glass required for prior-art
techniques, eliminates the need for further chemical processing,
has a low alkali content for reduced background noise, and is more
environmentally friendly due to the absence of lead.
2.1. ALD coated MCPs
The second breakthrough enabling next generation MCPs was
the advent of atomic layer deposition (ALD) coating methods and
materials to coat or functionalize GCAs to impart the necessary
resistive and secondary emission properties, converting them into
highly effective MCPs with electronic gain and robust performance
properties suitable for large area time of flight detector applica-
tions. ALD is a self-limiting, thin film deposition technique that
sequentially applies alternating layers of reactant precursor che-
micals to a surface to form a fully dense, conformal thin film. The
volatile precursor reactants are introduced into the reaction
chamber under reduced pressure. A key advantage of ALD is its
ability to coat small pores with high L/d ratios. Nanocomposite
ALD resistive coatings have been developed that meet all of the
requirements for large area MCPs [5,6].
Large area MCPs must exhibit uniform performance over the full
area of the device, and must be stable over time, irrespective of
thermal history, or operation under high voltage, and high electron
flux. ALD reactor design affects the flow dynamics and purging of
precursor chemicals and has a direct effect on the uniformity of the
resistive and emissive coatings. Subtle differences in the chemistry
of multi-laminate ALD coatings, including interactions between the
coatings and the glass substrate and can have a direct effect on the
performance of the MCPs.
Equipment and process modifications were made to a com-
mercial Beneq and custom-built ALD system to achieve coating
uniformity and performance stability over large area MCPs. Fig. 4
(left) shows the Beneq TFS 500 used in these studies, as well as a
fully functionalized 203 mm  203 mm MCP produced using these
techniques.
An important advantage of the ALD process for fabricating
MCPs is the ability to separately apply and independently optimize
the resistive and emissive layers, selecting from a wide variety of
material options. This is not the case for conventional MCPs where
a single lead sub-oxide resistive and emissive layer of variable
composition is developed during a hydrogen reduction forming
process.
3. Large area MCP performance results
The gain and spatial uniformity of functionalized MCP's are
evaluated in a high vacuum system equipped with calibrated UV
Window and photocathode
Indium Top Seal
Glass spacer #1
Glass spacer #2
Glass spacer #3
Top MCP
Glass sidewall
Bottom anode plate with conductive
strips penetrating seal
Bottom MCP
Fig. 1. LAPPD design features.
Fig. 2. (Left) Large-area, 203 mm square Incom GCA with 20 mm pores. (Right) Schematic of an MCP, showing the cascade of electrons generated from an incident electron.
M.J. Minot et al. / Nuclear Instruments and Methods in Physics Research A 787 (2015) 78–84 79
3. and electron sources and a photon counting /imaging readout anode.
Fig. 5 shows the “as deposited” gain curve for a 203 mm 203 mm
MCP (#C00043-004), consisting of a borosilicate glass substrate ALD
deposited with a resistive layer and MgO secondary electron emissive
(SEE) layer. The gain for fully processed “next generation MCPs”
(Fig. 7) is typically higher than achieved with commercial lead
glass MCPs.
3.1. Attributes of the MgO secondary electron emissive (SEE) layer
The secondary electron yield (SEY) for conventional lead sub-
oxide layers is $2 (two secondary electrons produced for each
primary electron striking the lead sub-oxide surface). The SEY of
ALD applied Al2O3 and MgO exhibit SEYs of 3 and 7 respectively,
and are dependent on the ALD coating thickness as shown [7] in
Fig. 6. In addition to the higher secondary electron yield exhibited
by MgO compared to Al2O3, the gain achieved with MgO increases
during high current extraction “burn in”.
The temporal stability of the MCP gain was examined by
monitoring the gain versus time under a uniform illumination.
The gain–voltage curves for “next generation” MCPs with an MgO
SEE layer was found to be stable after several weeks of operation
(Fig. 7 right) [8], and 1000 h of Nitrogen exposure. There is little
outgassing during high temperature bake-out (350C), and for MCPs
with an MgO SEE layer, the gain increases 10 fold during this bake-
out (Fig. 7 left). In contrast, conventional MCPs exhibit a sharp
initial decrease followed by a slow, gradual decay to a steady value.
As a consequence of this behavior, conventional MCPs require a
costly, time-consuming “scrubbing” treatment before they can be
put into service. In contrast, ALD-coated borosilicate glass MCPs
require significantly reduced scrubbing. After testing, storage under
nitrogen, and retesting, the gain remained the same without the
need for an initial or repeat burn-in (Fig. 7, left).
Fig. 8 is an MCP gain map taken using a cross delay line photon
counting anode. Excitation of the MCP under test is achieved with
185 nm non-uniform UV illumination. Image striping is due to the
anode period/charge cloud size modulation. The gain variability
Fig. 3. (Left) Incom manufactures large blocks of hollow glass capillary arrays (GCAs) with micron-sized pores. (Right) Each block can be sliced to produce approximately
140–150 GCA 203 mm  203 mm wafers that are later coated to produce high performance MCPs.
Fig. 4. (Left) Beneq ALD Coater, (right) fully coated MCP with resistive and emissive coatings, framed by a measurement and test fixture.
M.J. Minot et al. / Nuclear Instruments and Methods in Physics Research A 787 (2015) 78–8480
4. for this sample, over the 203 mm  203 mm area of the MCP is
o15%. This compares favorably with that achieved with much
smaller sized conventional MCPs currently available commercially.
The background for MCPs with borosilicate glass substrate is
typically 0.055 counts sÀ1
cmÀ2
, over 2000 s, for 2k  2k imaging
or about $5 times lower than standard (PbO) glass MCPs. This
lower background is attributed to the fact that the borosilicate
glass substrates have considerably less Potassium-40 compared to
the (PbO) glasses used for standard MCPs.
4. Fabrication of fully integrated sealed detector tiles
Integration of key device components including MCPs, photo-
cathode, spacers, getters, and the anode stripline detector, to form
a fully sealed detector tile, is presently done in collaboration with
the Experimental Astrophysics Group, Space Sciences Laboratory
(SSL), at University of California at Berkeley.
The bialkali photocathode used in these detectors is extremely
sensitive to chemical and thermal exposure. As a consequence, the
deposition of the photocathode must be done under ultra-high
vacuum (UHV) in a tank that has been rigorously cleaned, baked-
out and evacuated. Furthermore, once the photocathode is fabricated,
it cannot tolerate high temperatures. The final seal joining the top
window with photocathode applied, to the body tray containing the
MCPs, spacers and anode, is made with a low temperature melting
point alloy.
Device integration and sealing follows a multi-step procedure
that has been developed and reliably demonstrated over time at SSL
for smaller ceramic packages. Comparable processing applies to the
“all glass” package, including cleanliness and out-gassing proce-
dures of all components to eliminate virtual leaks, and to prepare
surfaces for deposition of well adhered, sensitive films as well as
wetting with metal alloys. The integration and sealing process
includes: (a) preparation of detector tube internal parts, (b) detector
internal stack assembly, and (c) bialkali photocathode deposition
and d) device sealing.
The first (ceramic) 203 mm  203 mm LAPPD tile integration
and sealing trial was initiated in July, 2013. Fig. 9 (right) shows QE
vs. wavelength for the photocathode deposited by co-evaporation
of bialkali components during fabrication of tube #1. Successful
deposition of several bialkali photocathodes with 20–25% QE at
350–400 nm and exhibiting 715% uniformity over the
203 mm  203 mm area plate was demonstrated. The QE
improves as the photocathode cools. Similar photocathodes
remained stable for over 5 months. Fig. 9 (left) plots the normal-
ized QE at each location on the window and shows that QE was
uniform within 715%, except where obscured by tooling during
deposition.
Once assembled and “sealed” the fully integrated tile was
measured and characterized while still under vacuum in the
UHV tank. Good gain uniformity was observed over the detector
with a few localized “hot spots”. Further testing was done with a
610 nm laser with a spot image of o5 mm FWHM at high pulse
amplitudes, show time resolution of 64 ps.
Unfortunately Tile #1 leaked when brought up to atmosphere
due to an incomplete alloy seal of the top window. This tile, with
readout electronics [9] is shown in Fig. 10 (left).
Several sealed tube detectors have now been built using “next
generation” borosilicate MCPs coated by ALD. Fig. 10 shows a fully
integrated sealed ceramic LAPPD, with Incom 203 mm  203 mm
MCP and readout electronics, as well as an image intensifier tube
[10] incorporating an 86.6 mm diameter, 10 m diameter por-
e  0.46 mm thick “next generation” MCP. In addition, SSL has
fabricated a 25 mm cross delay line readout sealed tube with an
opaque GaN photocathode deposited on “next generation” MCPs,
and has evaluated a commercial Photonis Planacon tube using a
pair of ALD borosilicate MCPs.
The results achieved with Tile #1, have been augmented with test
data from a fully integrated and working all glass “demountable”
detector system. This demountable detector is an O-ring sealed,
dynamically pumped detector tile test system [11] incorporating all
of the design features of the LAPPD, substituting an Aluminum metal
photocathode for bialkali. Table 1 summarizes actual demonstrated
results that have been achieved with LAPPD detectors as well as the
projected target performance expected for prototype LAPPD Tiles
being commercialized.
5. LAPPD commercialization
The high energy physics (HEP), scientific and medical commu-
nities have expressed interest in exploiting the availability of high
sensitivity photo-sensors with improved spatial and temporal
Fig. 5. “As deposited” gain curve for 203 mm  203 mm MCP (#C00043-004),
borosilicate glass substrate with ALD deposited Chem-1 resistive and MgO SEE layer.
Fig. 6. MgO and Al2O3 have high secondary electron yields (7 and 3 respectively)
which vary depending on thickness. By comparison, the SEY for conventional lead
oxide glass based MCPs is $2.
M.J. Minot et al. / Nuclear Instruments and Methods in Physics Research A 787 (2015) 78–84 81
5. resolution that can be scaled to large areas, and manufactured in a
robust, durable and compact package at a low cost. The availability
of large-area photodetectors with time resolutions below 10 ps and
space resolutions of o50 mm produced economically will enable
new techniques in HEP for multiple vertex separation and particle
identification at high-luminosity colliders, possible light collection in
heavy-noble-liquid ionization detectors, high-resolution electromag-
netic calorimeters, large non-cryogenic tracking neutrino detectors,
and combinatorial photon background rejection in rare kaon-decay
experiments. Other commercial applications of these devices will
include detectors for mass spectrometers, medical imaging (PET), as
well as neutron detection for scientific and homeland security (non-
proliferation) applications.
A recently held “Early Adopters Users” meeting [12] attracted
over 24 technical leaders and Principal Investigators, representing
17 High Energy Physics programs, demonstrating strong interest in
LAPPD™ for beta testing. “Early Adopters” divided into multiple
groups with different, but overlapping requirements depending on
the specific mission of their program. Some applications will require
high magnetic and radiation tolerance. Performance of LAPPD in
high magnetic and radiation fields remains to be demonstrated, and
will be evaluated by end users once prototype devices become
Fig. 7. (Left) Gain curves of MCP pair (20 mm pore, 60:1 L/d, 81 bias) at stages during preconditioning and nitrogen exposure. Right – UV scrub of ALD MCP pair 164–163,
(20 mm pore, 60:1 L/d, 81 bias).
Fig. 8. (Left) Average gain image “map” across the 8" Â 8" MCP (#C00043-004) made from borosilicate 20-mm pore GCA substrate, 60:1 L/d ratio and ALD deposited Chem-1
resistive coating, and MgO SEE layer. (Right) Gain uniformity along the X-axis and Y-axis. Showing o15% overall variation.
M.J. Minot et al. / Nuclear Instruments and Methods in Physics Research A 787 (2015) 78–8482
6. Fig. 9. (Right) QE vs. wavelength for photocathode deposited by co-evaporation of bialkali components during fabrication of tube #1. The QE improves as the photocathode
cools. Similar photocathodes remained stable for over 5 months. (Left) Normalized QE was uniform within 715%, except where obscured by tooling during deposition.
Fig. 10. (Left) Fully integrated sealed ceramic LAPPD, with Incom 203 mm  203 mm MCP & readout electronics (Gary Varner, University of Hawaii). (Right top and bottom)
Image intensifier tube: 86.6 mm diameter, 10 m diameter pore  0.46 mm thick Incom MCP.
Table 1
Demonstrated results and target performance for LAPPD tiles.
Parameter Demonstrated results “Standard” LAPPD 20 lm Φ pores & future targets
MCP Functional area 200 mm  200 mm  1.2 mm, 20 mm pore, pitch¼25 m, OAR¼65%, flat712.7 mm, resistive layer: 10–25 MΩ, optional SEE layer:
MgO or Al2O3
MCP gain 105
@ 1400 V, 107
@ 2000 V, chevron pair
MCP gain uniformity o15% edge to edge variability
MCP background
rates
3000 s background, 0.085 events cmÀ2
sÀ1
at 7 Â 106
gain, 1025v bias on each MCP. MCP background rate is about 35 kHz at the highest running
gain.
QE 20–25% QE @350–400 nm, 715% uniformity over 200 mm  200 mm area
Spatial resolution 1 mm for large signals, 5 mm for single photons (application specific) (with PSEC4 or PSEC5 read-out electronics and software algorithms)
Timing resolution 64 ps demonstrated single-photon, scales as 1/N; single-photon target¼ r40 ps(610 nm laser, spot image of o5 mm, FWHM at high pulse
amplitudes)
M.J. Minot et al. / Nuclear Instruments and Methods in Physics Research A 787 (2015) 78–84 83
7. available. There was general agreement however, that LAPPD design
features should translate into a lower cost product compared to
other MCP based photodetectors currently available. Furthermore,
with continued development, the underlying technology appears to
be amenable to still higher performance. Future pricing will depend
on demonstrating an effective, high yield manufacturing process,
with sufficient volumes to take advantage of economies of scale.
Despite these uncertainties, it is already clear that the identified
need translates into meaningful market demand.
The design, construction and commissioning of facilities neces-
sary for pilot production of LAPPD is now underway at Incom Inc.
These include expanded facilities to fabricate GCA's, functionalize
them with ALD coatings to produce MCPs, and UHV tile integration
and sealing facility for LAPPDs. Detector tile integration and sealing
trials are planned with a target of demonstrating fully integrated
sealed LAPPD detectors in fall 2014. General availability of prototype
LAPPDs will be determined by the progress of the commercializa-
tion program described here but plans call for demonstrating pilot
production of LAPPDs in 2015 and the delivery of initial LAPPD tiles
to early adopters in 2016.
Acknowledgment
The authors would like to thank the U.S. Department of Energy
for their continued financial support [13] Funding and the coopera-
tion of the many institutions (Argonne National Laboratory, Uni-
versity of California at Berkeley, University of Chicago, University of
Hawaii and Fermilab) that that have contributed to this work.
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M.J. Minot et al. / Nuclear Instruments and Methods in Physics Research A 787 (2015) 78–8484