Introduction to Microprocesso programming and interfacing.pptx
Seminar report on CNTs 2017
1. i
“Towards Global Technological Excellence”
A
Seminar Report On
“CARBON NANOTUBES IN SOLAR PANEL
TECHNOLOGY”
For the Degree of Bachelor of Technology
By
Mr. Saurabh Muniraj Bansod (14003009)
Under the Guidance of
Prof. A. S. Sindekar
Department of Electrical Engineering
GOVERNMENT COLLEGE OF ENGINEERING,
AMRAVATI
(An Autonomous Institute of Government of Maharashtra)
(2017-18)
2. ii
GOVERNMENT COLLEGE OF ENGINEERING,
AMRAVATI
(An Autonomous Institute of Government of Maharashtra)
DEPARTMENT OF ELECTRICAL ENGINEERING
CERTIFICATE
This is to certify that the seminar report entitled, “Carbon Nanotubes in Solar Panel
Technology” which is being submitted by Mr. Saurabh Muniraj Bansod (14003009) under my
supervision and guidance during the academic year of 2017-18 in satisfactory manner.
Prof. A. S. Sindekar Prof. A. S. Sindekar
(Seminar Guide) (Head of Department)
3. iii
DECLARATION
I hereby declare that the seminar report entitled “Carbon Nanotubes in Solar Panel Technology”
has been written by me under the guidance of Prof. A. S. Sindekar, Head Of Department of
Electrical Engineering, for the course of Seminar (EEU709) as a requirement of VII semester.
Mr. Saurabh Muniraj Bansod
Place: Amravati (ID-14003009)
Date:
4. iv
ACKNOWLEDGEMENT
I am obliged to our Head of the department Prof. A. S. Sindekar for giving this great opportunity.
I am grateful for his cooperation during the period of my assignment.
I also thank every one of my batch for their cooperation, support and for their constant
encouragement without which this assignment would not be possible. I take this opportunity to
express my profound gratitude and deep regards to my guide Prof. A. S. Sindekar for his exemplary
guidance, monitoring and constant encouragement throughout the course of this seminar.
I also acknowledge our profound sense of gratitude to all staff members who have been providing
me the technical knowledge and moral support to complete the seminar report with full
understanding.
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INDEX
Chapter No. Content Page
No.
1 Introduction 1
2 Literature Survey 3
3 Concept, Functional and Technical details and
Methods of Carbon Nanotubes
6
3.1 Concept 6
3.2 Functional and technical details 7
3.2.1 Single-Walled Nanotubes (SWNTs) 7
3.2.1 Multi-Walled Nanotubes (MWNTs) 8
3.2.3 Other carbon nanotubes structures 10
3.3 Methods of Nanotubes 13
3.3.1 Arc Discharge method 13
3.3.2 Laser ablation 14
3.3.3 Chemical Vapor Deposition (CVD) 15
4 Result 17
5 Conclusion 19
References 20
6. vi
LIST OF FIGURES
Fig. No. Title Page
No.
3.1 .a) Single-walled Carbon Nanotubes 8
3.1 .b) Multi-Walled Carbon Nanotubes 9
3.2 .a) Torus 10
3.2 b) Nanobud 11
3.2 c) Nitrogen doped nanotubes 12
3.3.a) Arc discharge method 14
3.3.b) Laser ablation 15
3.3.c) Chemical vapor deposition (CVD) 16
4.1 IV characteristics of the cells as indicated. b) Power
delivered to the load for all cells as described in the
legend for a).
18
8. 1
CHAPTER 1
INTRODUCTION
This chapter provides a quick introduction about carbon nanotubes structures, and need of carbon
nanotubes in solar panel technology.
Carbon nanotubes (CNTs) take the form of cylindrical carbon molecules and have novel properties
that make them potentially useful in a wide variety of applications in nanotechnology, electronics,
optics, and other fields of materials science. They exhibit extraordinary strength and unique
electrical properties, and are efficient conductors of heat. Inorganic nanotubes have also been
synthesized.
Carbon nanotubes (CNTs) are allotropes of carbon with a cylindrical nanostructure. Nanotubes
have been constructed with length-to-diameter ratio of up to 132,000,000:1, significantly larger
than for any other material. These cylindrical carbon molecules have unusual properties, which are
valuable for nanotechnology, electronics, optics and other fields of materials science and
technology. In particular, owing to their extraordinary thermal conductivity and mechanical and
electrical properties, carbon nanotubes find applications as additives to various structural
materials. For instance, nanotubes form a tiny portion of the material(s) in some (primarily carbon
fiber) baseball bats, golf clubs, or car parts.
Nanotubes are members of the fullerene structural family. Their name is derived from their long,
hollow structure with the walls formed by one-atom-thick sheets of carbon, called graphene. These
sheets are rolled at specific and discrete ("chiral") angles and the combination of the rolling angle
and radius decides the nanotube properties; for example, whether the individual nanotube shell is
a metal or semiconductor.
Nanotubes are categorized as single-walled nanotubes (SWNTs) and multi-walled nanotubes
(MWNTs). Individual nanotubes naturally align themselves into "ropes" held together by van der
Waals forces, more specifically, pi-stacking.
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Applied quantum chemistry, specifically, orbital hybridization best describes chemical bonding in
nanotubes. The chemical bonding of nanotubes is composed entirely of sp2 bonds, similar to those
of graphite. These bonds, which are stronger than the sp3 bonds found in alkanes and diamond,
provide nanotubes with their unique strength.
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CHAPTER 2
LITERATURE SURVEY
This chapter includes the literature survey about the carbon nanotubes, and its applications with
the help of research papers.
Ref [1] Al Palaniappan D.W.H. Fam, A. I. Y. Tok, B. Lied Berg, S.M. Moochhala, focused on the
recent progress in the field of CNT research in connection to surface modification, control
synthesis, functionalization and sensor development. He reported that the surface area enlargement
and the control of morphology are the key features which influence the performance of the device.
The fabrication of a sensor deals with combining the morphology of CNT by control synthesis
techniques with a supporting substrate and electrode interconnections present in a transistor.
Ref [2]. I.Sayago, E. Terrado, M. Alexandre, M.C. Horrillo, M. J. Fernandez, J. Lozano, reported
that development of a resistive sensor based on CNT as active sensing element for the detection of
hydrogen gas. The impact of ageing, thermal treatments and the employed carrier gas was
analyzed. The sensor response variation during exposure of various concentration of hydrogen in
nitrogen atmosphere at room temperature was discussed. It was found that the variation in
resistance was high at 250 oC than higher temperatures. Aged sensors provided a good response
to hydrogen and excellent selectivity with respect to the exposed gases. The sensor operation
temperature reduced the response, but lead to faster detection and also leads to shorter recovery
times.
Ref [3]. S.R. Ahmad, A. M. Keszler, L. Nemes, X. Fang, reported the case study of multiwalled
and single walled samples of CNT characterization by Raman spectroscopy and microscopy.
Raman spectroscopy had proved to be a powerful tool in understanding of CNT, based on vibration
and electronic properties of pure sp2 and sp3 hybridized Carbon allotropes of graphite and
diamond. The multiwall samples were prepared by metal oxide catalyzed decomposition of
11. 4
acetylene at 1000 K. This yielded thick bundles of multiwall tubes, which were purified to remove
metal oxide and metal particles, but contained significant amounts of amorphous Carbon. The
Raman spectra of CNTs contained first-order and higher-order features attributed to the vibration
excitation of fundamental and composite excitations (overtone and combination tones
respectively). The Raman spectra of graphite sample taken with 514.5 nm argon ion laser light
was discussed and the slight dispersion of the Raman bands upon laser excitation energy changes
can be increased by using a broader range of excitation wavelengths.
Ref [4]. Marcus.D.Lay, Deepa Vairavapandian, Pornnipa Vichchulada, reviewed the recent
advancement and applications of modified Carbon nanotubes in the field of catalysis and gas
sensing. Carbon nanotubes possess small size, large surface area and high aspect ratio and show
high sensitivity even to small concentration of gas. The unique geometry of Carbon nanotube
supports the attachments and distribution of nanoparticle on to its surface. He reported the
importance of electrochemical deposition which controlled the particle size and its distribution
based on the potential applied, time of deposition and concentration of the solution. Surface
modified CNT acted as a sensing device working on the principle of chemiresistance, due to the
transfer of charge between the Carbon nanotube and the gas analyte, the electrical conductivity
varied which was the gas sensing mechanism of chemiresistive sensors resulting in production of
an electrical signal.
Ref [5]. Sudobh Srivastava, S.S. Sharma, Sumit Kumar, Shweta Agrawal, M. Singh, Y.K.Vijay
reported that MWCNT doped with polyaniline composite thin films for detection of hydrogen gas.
The gas sensitivity of this composite film was evaluated by measuring the change in electrical
resistance of composite films in the presence of hydrogen gas for various pressures at room
temperature. The variation in resistance as a function of time and sensitivity in terms of normalized
resistance for MWCNT doped polyaniline sensor and pure polyaniline sensor at room temperature
was compared.
The sensitivity as a function of time for different pressures (2.72, 3.40, 4.08 atom) was reported.
Initially, the sensitivity increased and then saturated. Camphor sulfonic acid doped polyaniline
interacts with hydrogen enhanced charge transfer, resulting in resistance decrease in thin films. It
is observed that MWCNT doped with polyaniline composite film showed a higher response to
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hydrogen gas in comparison to pure polyaniline. The sensitivity of pure polyaniline and MWCNT-
polyaniline composite sensor decreased on the increase in hydrogen gas pressures.
Ref [6]. A. Chowdhury, V. Gupta, K. Sreenivas, R. Kumar, S. Mazumdar, P.K. Patanjali, prepared
MWCNT attached to NH2/ITO substrate which can be utilized as an effective electrode.
Ultrasonication of the sample lead to enhancement of MWCNT loading on the ITO surface in a
uniform manner. The paper reported the electrochemical activity of uric acid on MWCNT
composite. The presence of amino ion on the sample surface was confirmed from XPS and Fourier
transforms infra-red spectroscopy. It was found that the amino-ion interacts with MWCNT in an
electrostatic manner.
13. 6
CHAPTER 3
FUNCTIONAL AND TECHNICAL DETAILS OF CARBON
NANOTUBES
This chapter gives the information about concept, functional and technical details, and some
importance method of carbon nanotubes.
3.1 Concept
Carbon comes from Latin word “carbo” which is delivered from a French word “charbon”,
meaning charcoal.It is fourth most abundant chemical element in the universe by mass, after
hydrogen, helium and oxygen.
Carbon nanotubes (CNTs) are allotropes of carbon with a cylindrical nanostructure. Nanotubes
have been constructed with length-to-diameter ratio of up to 132,000,000:1, significantly larger
than for any other material. These cylindrical nanotubes have unusual properties, which are
valuable for nanotechnology, electronics, optics and other fields of technology. In particular,
owing to their extraordinary thermal conductivity and mechanical and electrical properties, carbon
nanotubes find applications as additives to various structural materials. For instance, nanotubes
form a tiny portion of the material(s) in some (primarily carbon fiber) baseball bats, golf clubs, or
car parts. These carbon nanotubes are now used in the technology of solar panels to increase the
efficiency of the solar panels up to 80%. The discussion mentioned ahead will help in
understanding how these carbon nanotubes can be used in solar panels.
Nanotubes are member of the fullerene structural family. Their name is delivered from their long,
hollow structure with the walls formed by one-atom-thick sheets of carbon, called graphite.
Carbon nanotubes are categorized as single-walled nanotubes (SWNTs) and multi-walled
nanotubes (MWNTs).Applied Quantum chemistry, specifically, orbital hybridization best
describes chemical bonding in nanotubes. The chemical bonding of nanotubes involves entirely
14. 7
sp2-hybrid carbon atoms. These bond which are similar to those of graphite and stronger than those
found in alkanes and diamond, provide nanotubes with their unique strength.
3.2 Functional and technical details
Carbon nanotubes are mainly classified into two types:-
1. Single-walled Nanotubes (SWNTs)
2. Multi-walled Nanotubes (MWNTs)
3.2.1 Single-Walled Nanotubes (SWNTs)
A single-walled carbon nanotube (SWNT) may be thought of as a single atomic layer thick
sheet of graphite (called grapheme) rolled into a seamless cylinder.
Most single-walled nanotubes (SWNT) have a diameter of close to 1 nanometre, with a
tube length that can be many millions of times longer.
Single-walled nanotubes are an important variety of carbon nanotube because they exhibit
electrical that are not shared by the multi-walled carbon nanotubes (MWNT) variant.
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Fig.3.1 a). Single-walled Carbon Nanotubes
3.2.2 Multi-Walled Nanotubes (MWNTs)
Multi-walled nanotubes (MWNT) consist of multiple rolled layers (concentric tubes) of
graphite.
There are two models which can be used to describe the structures of multi-walled
nanotubes.
In the Russian Doll model, sheets of graphite are arranged in concentric cylinders.
16. 9
In the Parchment model, a single sheet of graphite is rolled in around itself, resembling a
scroll of parchment or a rolled newspaper.
The telescopic motion ability of inner shells and their unique mechanical properties will
permit the use of multi-walled nanotubes as main movable arms in coming Nano
mechanical devices.
Fig.3.1 b) Multi-Walled Carbon Nanotubes
17. 10
3.2.3 Other Carbon Nanotubes Structures
In other carbon nanotubes structures classified into three categories,
a) Torus
b) Nanobud
c) Nitrogen doped nanotubes
a) Torus
Carbon nanotube bent into a torus (doughnut shape).Nanotori are predicted to have many unique
properties, such as magnetic moments 1000 times larger than previously expected for certain
specific radii. Properties such as magnetic moment, thermal stability, etc. vary widely depending
on radius of the torus and radius of the tube.
Fig 3.2 a) Torus
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b) Nanobud
Carbon Nanobud are a newly created material combining two previously discovered
allotropes of carbon, carbon nanotubes and fullerenes. In this new material, fullerene-like "buds"
are covalently bonded to the outer sidewalls of the underlying carbon. They good field emitters.
In composite materials, the attached fullerene molecules may function as molecular anchors
preventing slipping of the nanotubes, thus improving the composite’s mechanical properties.
Fig 3.2 b) Nanobud
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c) Nitrogen doped nanotubes
N-doping provides defects in the walls of CNT's allowing for Li ions to diffuse into inter-wall
space. It also increases capacity by providing more favorable bind of N-doped sites. N-CNT's are
also much more reactive to metal oxide nanoparticle deposition which can further enhance storage
capacity, especially in anode materials for Li-ion batteries. However Boron doped nanotubes have
been shown to make batteries with triple capacity.
3.2 c) Nitrogen doped nanotubes
20. 13
3.3 Methods of Nanotubes
Techniques have been developed to produce nanotubes, Including arc discharge, laser ablation
and chemical vapor deposition (CVD). Most of these processes take place in vacuum or with
process gases. CVD growth of CNTs can take place in vacuum or at atmospheric pressure. Large
quantities of nanotubes can be synthesized by these methods; advances in catalysis and
continuous growth processes are making CNTs more commercially viable.
3.3.1 Arc Discharge method
The nanotubes were initially discovered using this technique; it has been the most widely-used
method of carbon nanotubes.
Two Graphite electrodes placed in an inert Helium atmosphere.
When DC current is passed anode is consumed and material forms on cathode.
For SWNT mixed metal catalyst is inserted into anode.
Pure iron catalyst + Hydrogen-inert gas mixture gives 20 to 30cm long tube.
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Fig 3.3 a) Arc discharge method
3.3.2 Laser ablation
In the laser ablation process, a pulsed laser vaporizes a graphite target in a high-
temperature reactor while an inert gas is bled into the chamber.
Nanotubes develop on the cooler surfaces of the reactor as the vaporized carbon condenses.
A water-cooled surface may be included in the system to collect the nanotubes.
The laser ablation method yields around 70% and produces primarily single-walled carbon
nanotubes with a controllable diameter determined by the reaction temperature.
It is more expensive than either arc discharge or chemical vapor deposition.
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Fig 3.3 b) Laser ablation
3.3.3 Chemical Vapor Deposition (CVD)
During CVD, a substrate is prepared with a layer of metal catalyst articles, most commonly
nickel, cobalt, iron, or a combination.
The diameters of the nanotubes that are to be grown are related to the size of the metal
particles.
The substrate is heated to approximately 700°c.
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To initiate the growth of nanotubes, two gases are bled into the reactor: a process gas (such
as ammonia, nitrogen or hydrogen) and a carbon-containing gas (such as acetylene,
ethylene, ethanol or methane).
Nanotubes grow at the sites of the metal catalyst;
The carbon-containing gas is broken apart at the surface of the catalyst particle, and the
carbon is transported to the edges of the particle, where it forms the nanotubes.
Fig 3.3 c) Chemical Vapor Deposition (CVD)
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CHAPTER 4
RESULT
We present experimental demonstration of power generation obtained under ambient
conditions at solar noon CNT-only cells: cells are built with identical geometry but different CNT
film compositions and thickness. This highlights how film composition affects cell performance.
Optimized cells: cells are built with the same CNT film thickness and composition, but with
differences in construction techniques to isolate its role in cell efficiency.
CNT-Only Cells the photocurrent I decreases linearly with increasing cell potential applied
to the load V . We extract the open circuit voltage VOC by extrapolating the I{V characteristic to
I~0 and the short-circuit current ISC by extrapolating to V~0 (table 1). Both ISC and VOC of the
enriched mixture cells increase with decreasing CNT coverage of the semiconducting active
electrode. Similarly, the high-density cell of the regular mixture of nanotubes has a lower ISC and
VOC than the low-density cell. The power transfer curves show a peak power transfer of
Optimized cells
We have studied cells with different construction techniques, using CNT electrodes from the
same batch. Similar techniques were employed for data analysis as above ( table 2). The power
transfer curves show a peak power transfer Pmax at R~Rmax. Gold Guard Ring. The presence of
the gold guard ring increases ISC by a factor *2:5, while
Table4. 1: parameters of CNSCs
25. 18
Table 4.2 optimized CNSCs
Fig 4.1 IV characteristics of the cells as indicated. b) Power delivered to the load
for all cells as described in the legend for a).
doi:10.1371/journal.pone.0037806.t002
26. 19
Pmax that occurs when the impedance of the load reaches Rmax. The low-density enriched
as well as the low-density regular cells deliver more power to the load than their high-density
counterparts. This is consistent with both ISC and VOC being larger VOC remains approximately
constant. Rmax is lower by *3:5 and Pmax is *2 times greater. Graphite Counter Electrode. Both VOC
and ISC are greater than the normally constructed cell and Pmax is *12 times greater. Thin Cell. When
the enriched side is facing the incident solar radiation (‘‘up’’), the power is slightly larger than
when the regular side is facing the incident radiation (‘‘down’’). Both VOC and ISC are lower by
factors of *5 and *3, which in itself is undesirable. However, optimum power transfer occurs at a
much lower resistance.
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CHAPTER 5
CONCLUSION
Nanotubes appear destined to open up a host of new practical applications and help
improve our understanding of basic physics at the nonmetric scale.
Nanotechnology is predicted to spark a series of industrial revolutions in the next two decades that
will transform our lives to a far greater extent than silicon microelectronics did in the 20th century.
Carbon nanotubes could play a pivotal role in this upcoming revolution if their remarkable
structural, electrical and mechanical properties can be exploited.
The remarkable properties of carbon nanotubes may allow them to play a crucial role in
the relentless drive towards miniaturization scale.
Lack of commercially feasible synthesis and purification methods is the main reason that
carbon nanotubes are still not widely used nowadays.
At the moment, nanotubes are too expensive and cannot be produced selectively. Some of
the already known and upcoming techniques look promising for economically feasible production
of purified carbon nanotubes.
Some future applications of carbon nanotubes look very promising. All we need are better
production technique for large amounts of purified nanotubes that have to be found in the near
future. Nanotube promises to open up a way to new applications that might be cheaper, lower in
weight and have a better efficiency.
5.1 Applications of carbon nanotubes (CNTs)
Carbon nanotube Membranes for Transdermal Drug Delivery
Carbon nanotubes used for cancer treatment
CNTs for Cardiac Autonomic Regulation
CNTs for platelet activation
CNTs for Tissue Regeneration
Carbon nanotubes in drug Delivery: Future trends
It is used in Micro-electronics / semiconductors
Conducting Composites
28. 21
Artificial muscles
Super capacitors
Batteries
Magnetic nanotube
Reinforcement of armour and other materials
Reinforcement of polymer
Carbon nanotubes Filtration for water purification
5.2 Advantages of carbon nanotubes (CNTs)
Extremely small and lightweight.
Resources required to produce them are plentiful, and many can be made with only a small
amount of material.
Are resistant to temperature changes, meaning they function almost just as well in extreme
cold as they do in extreme heat.
Improves conductive, mechanical, and flame barrier properties of plastics and composites.
Enables clean, bulk micromachining and assembly of components.
Improves conductive, mechanical, and flame barrier properties of plastics and composites.
5.3 Disadvantages of carbon nanotubes (CNTs)
Despite all the research, scientists still don't understand exactly how they work.
Extremely small, so are difficult to work with nanotubes.
29. 22
Currently, the process is relatively expensive to produce the nanotubes.
Would be expensive to implement this new technology in and replace the older technology in
all the places that we could.
At the rate our technology has been becoming obsolete, it may be a gamble to bet on this
technology.
30. 23
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