1) The document summarizes a study using Kelvin Probe Force Microscopy (KPFM) to measure charge motion in real-time in organic thin films.
2) KPFM allows measurement of local surface potentials to observe how charges screen an applied gate voltage in materials like P3HT and PDI-CN2.
3) For a p-type material like P3HT, application of a negative gate leads to an initial negative potential that is quickly screened by holes rushing in, while application of a positive gate leads to holes leaving and a positive potential.
The Quantum Internet: Hype or the Next StepJohn Ashmead
What do we mean by the quantum internet? Why do we need more than just quantum computing? What are quantum cryptography, quantum key distribution, quantum sensors? How are these concepts entangled? What are the advantages of the quantum internet? key problems? Who will get to use it? And do we have just a bunch of interesting technologies that all have quantum in their name or can the whole be more than the sum of its parts?
The Arrival of Quantum Computing – Quantum NetworksImpact.Tech
Quantum Networks by Jeremy Wittmer.
Slides from the Impact.tech seminar about quantum computing. The presentation addresses the technology behind quantum networks and the possibilities they provide.
Impact.tech Launch Seminars are meant to give entrepreneurs and investors a launch into a topic where they can apply their skills to make a major positive impact for humanity and the world.
This is the last keynote address I made at the International Medical Informatics Conference (MEDINFO).The speech presented the areas in which eHealth can contributed to health and well-being, the emerging trend of using big data in health and examples of how big data from mobile phones, social media and internet have been used.
Presentation made by Keith Cressman at the 40th session of the FAO Desert Locust Control Committee (DLCC) on the FAO Commission for Controlling the Desert Locust in South-West Asia, SWAC (20 June 2012).
The Quantum Internet: Hype or the Next StepJohn Ashmead
What do we mean by the quantum internet? Why do we need more than just quantum computing? What are quantum cryptography, quantum key distribution, quantum sensors? How are these concepts entangled? What are the advantages of the quantum internet? key problems? Who will get to use it? And do we have just a bunch of interesting technologies that all have quantum in their name or can the whole be more than the sum of its parts?
The Arrival of Quantum Computing – Quantum NetworksImpact.Tech
Quantum Networks by Jeremy Wittmer.
Slides from the Impact.tech seminar about quantum computing. The presentation addresses the technology behind quantum networks and the possibilities they provide.
Impact.tech Launch Seminars are meant to give entrepreneurs and investors a launch into a topic where they can apply their skills to make a major positive impact for humanity and the world.
This is the last keynote address I made at the International Medical Informatics Conference (MEDINFO).The speech presented the areas in which eHealth can contributed to health and well-being, the emerging trend of using big data in health and examples of how big data from mobile phones, social media and internet have been used.
Presentation made by Keith Cressman at the 40th session of the FAO Desert Locust Control Committee (DLCC) on the FAO Commission for Controlling the Desert Locust in South-West Asia, SWAC (20 June 2012).
Послуги і можливості компанії "Електронні архіви України" з оцифрування фотоальбомів, негативів, слайдів, ювелірних предметів, мап, букіністики. Подробиці - www.elau.org
My presentation together with my group on the problem of low production which was faced by the Danshui plant 2 which produced Iphones and the decisions we suggested if we were managers
CMOS logic scaling is reaching a point with gradually diminishing returns. So that is why so-called Beyond CMOS compute paradigms have gained a lot of attention in the last decade. It is however far from trivial to beat advanced ultimately-scaled CMOS logic realisations. Plasmonics wave computing is one potential emerging option which could have better area-performance metrics for high performance computing and especially exascale computing servers. In this talk a review will be provided of the current status of this technology and why and where it could be beneficial.
Послуги і можливості компанії "Електронні архіви України" з оцифрування фотоальбомів, негативів, слайдів, ювелірних предметів, мап, букіністики. Подробиці - www.elau.org
My presentation together with my group on the problem of low production which was faced by the Danshui plant 2 which produced Iphones and the decisions we suggested if we were managers
CMOS logic scaling is reaching a point with gradually diminishing returns. So that is why so-called Beyond CMOS compute paradigms have gained a lot of attention in the last decade. It is however far from trivial to beat advanced ultimately-scaled CMOS logic realisations. Plasmonics wave computing is one potential emerging option which could have better area-performance metrics for high performance computing and especially exascale computing servers. In this talk a review will be provided of the current status of this technology and why and where it could be beneficial.
Atomic level manipulation of matter using Scanning Transmission Electron Micr...Ondrej Dyck
Discussion of developments surrounding the transformation of the scanning transmission electron microscope from an imaging platform into a manipulation platform.
These are the slides from the webinar hosted by NNIN @ University of Michigan on May 28, 2013. Find out more about my views on how atomic-scale modeling can help the development of nanoelectronics based on nanowires, interfaces, graphene. The special Atomistix ToolKit
Presentation of PhD Thesis: "A perspective on metasurfaces, circuits, holograms and invisibility". Carlo Andrea Gonano, Politecnico di Milano, Italy, 26 January 2016.
Current Monitoring for Power GaN Transistors-SenseGaN TechniqueMehrdad Biglarbegian
A quick overview of the current sensing in power electronics converters is tested and analyzed. Then, SenseGaN technique along with the integration of semiconductors to monitor the power GaN module current without significant effects on power stage performance and opens a new era for smart devices in future power electronics. Various application for soft switching with this current measurement technique is also proposed.
1. Charge motion in Poly(3-hexylthiophene-2,5-diyl)
studied with Scanning Probe Microscopy
Jason Moscatello, Chloe Castaneda, Katherine Aidala
APS March Meeting
Session L41: Focus Session: Organic Electronics and Photonics - Transport in Polymer Thin Films
Wednesday, March 4, 2015 9:12AM
2. Organic potential
Organic electronics can be used in many applications we cannot use traditional
silicon architectures.
For example: Large-area, low-cost electronics
Printed electronics
Flexible electronics
Transparent electronics
Image Source: Techradar.com ImageSource: National Research Council Canada
jmoscate@mtholyoke.edu
3. Why SPM?
jmoscate@mtholyoke.edu
Image Source: Agilent
Organics are an inherently disordered system
with many local effects such as:
• Trap states
• Contact resistance
• Carrier density dependent mobility
• Environment environment/interface
SPM techniques are capable of measuring local
effects.
Allows us to focus on electrical interactions in
order to follow charges.
4. Kelvin Probe Force Microscopy (KPFM)
• a local surface potential measurement
• measured relative to tip potential
Measuring Potentials
jmoscate@mtholyoke.edu
6. Measuring Potentials
jmoscate@mtholyoke.edu
-1 V
3 V
-1 V
-1 V
Vtip = Vsample
0
Kelvin Probe Force Microscopy (KPFM)
• a local surface potential measurement
• measured relative to tip potential
minimize oscillation
Force at resonant
frequency, ωac
7. KPFM in Space and Time
jmoscate@mtholyoke.edu
Pass 1:
Topography
40
35
30
25
20
µm
403020100
µm
-40
-20
0
20
40
nm
40
35
30
25
20
µm
403020100
µm
0.8
0.7
0.6
0.5
0.4
0.3
V
Pass 2:
KPFM
1. Topography
2. KPFMImage Source: Asylum Research
Device On
v
Au AuP3HT
Au AuP3HT
2
1
8. jmoscate@mtholyoke.edu
Potential
Time
?
v = 0
Event
Pass 1:
Topography
40
35
30
25
20
µm
403020100
µm
-40
-20
0
20
40
nm
40
35
30
25
20
µm
403020100
µm
0.8
0.7
0.6
0.5
0.4
0.3
V
Pass 2:
KPFM
1. Topography
2. KPFMImage Source: Asylum Research
v
2
1
KPFM in Space and Time
Device On
Au AuP3HT
Au AuP3HT
9. P3HT Organic Field Effect Transistor (OFET)
P3HT ≥96% RR
>32k MW
D S
G (n-type Si, .01 Ω-cm)
200 nm thermally
grown SiO2
Au
poly(3-hexylthiophene)
jmoscate@mtholyoke.edu
10. Real Time Screening - Controls
• No P3HT
• Tip above metal electrode
• Gate turned on and off
D S
G
Tip
Expect to see 0V above the Au, because the electrons
move too quickly to resolve, screening the back-gate.
grounded
Apply -7V
grounded
jmoscate@mtholyoke.edu
11. Real Time Screening - Controls
• No P3HT
• Tip above metal electrode
• Gate turned on and off Tip
No change in measured potential
Apply -7V
D S
G
Expect to see 0V above the Au, because the electrons
move too quickly to resolve, screening the back-gate.
jmoscate@mtholyoke.edu
12. Real Time Screening - Controls
• No P3HT
• Tip above bare dielectric
• Gate turned on and off
D S
G
What happens for the same sequence, but above the
dielectric?
Tip
jmoscate@mtholyoke.edu
13. Real Time Screening - Controls
• No P3HT
• Tip above bare dielectric
• Gate turned on and off
D S
G
What happens for the same sequence, but above the
dielectric?
Tip
t = 3 ms
Cannot
screen
jmoscate@mtholyoke.edu
14. Real Time Screening – P3HT
D S
G
What will KPFM measure when the tip is above a poor conductor, which is
connected to grounded metal electrodes?
Tip
Can you record the screening as the carriers move
through the film?
P3HT
Au
jmoscate@mtholyoke.edu
15. For a material with holes as the majority carrier:
Real Time Screening – P3HT
jmoscate@mtholyoke.edu
16. Negative gate
Initial negative potential
Then holes rush in to screen
For a material with holes as the majority carrier:
Real Time Screening – P3HT
jmoscate@mtholyoke.edu
17. Vg = 0
Initial surplus of holes
Positive potential
Holes leave the film
For a material with holes as the majority carrier:
Real Time Screening – P3HT
jmoscate@mtholyoke.edu
Negative gate
Initial negative potential
Then holes rush in to screen
18. Vg = 0
Initial surplus of holes
Positive potential
Holes leave the film
For a material with holes as the majority carrier:
Real Time Screening – P3HT
jmoscate@mtholyoke.edu
Negative gate
Initial negative potential
Then holes rush in to screen
19. Vg = 0
Initial surplus of holes
Positive potential
Holes leave the film
Positive gate
Initial positive potential
Holes leave film to screen
For a material with holes as the majority carrier:
Real Time Screening – P3HT
jmoscate@mtholyoke.edu
Negative gate
Initial negative potential
Then holes rush in to screen
20. Vg = 0
Initial surplus of holes
Positive potential
Holes leave the film
Positive gate
Initial positive potential
Holes leave film to screen
Too few holes
Negative potential
Holes rush in
Vg = 0
For a material with holes as the majority carrier:
Real Time Screening – P3HT
Negative gate
Initial negative potential
Then holes rush in to screen
jmoscate@mtholyoke.edu
22. Real Time Screening – PDI-CN2
electrons
Vgs > 0
jmoscate@mtholyoke.edu
Initial positive potential
then electrons rush in to screen
Electron surplus leads to
Initial negative potential
Electrons leave the film
PDI-CN2
23. Real Time Screening – PDI-CN2
electrons
Vgs > 0
jmoscate@mtholyoke.edu
Initial positive potential
then electrons rush in to screen
Electron surplus leads to
Initial negative potential
Electrons leave the film
PDI-CN2
24. Real Time Screening – PDI-CN2
jmoscate@mtholyoke.edu
holes
Vgs < 0
electrons
Vgs > 0
PDI-CN2
P3HT
26. Real Time Screening – PDI-CN2
jmoscate@mtholyoke.edu
Initial negative potential
Electrons leave film to screen
Too few electrons
Positive potential
Electrons rush in
electrons
Vgs < 0
PDI-CN2
27. Real Time Screening – PDI-CN2
jmoscate@mtholyoke.edu
holes
Vgs > 0
P3HT
electrons
Vgs < 0
PDI-CN2
29. Ongoing & Future Studies
jmoscate@mtholyoke.edu
The affect of bias stress in N2 environment on P3HT OFETs.
How does it change in ambient with or without stress? a
30. Ongoing & Future Studies
jmoscate@mtholyoke.edu
Other materials, such as PbS
quantum dots.
With Scott Geyer, Moungi Bawendi, and
Vladimir Bulovic (MIT).
P3HT
31. jmoscate@mtholyoke.edu
Ongoing & Future Studies
How does tip distance affect measurement?
Can we distinguish between contact-limited and bulk-limited transport?
VGS = 0V VGS = -6V VGS = 0V
outward
outward
32. Thank You
NSF CAREER Award DMR-0955348
Thank you!
jmoscate@mtholyoke.edu
Chloe Castaneda
Katherine Aidala