Report of Infrared plastic solar cell

INFRARED PLASTIC SOLAR CELL

2014-15

CHAPTER 1

INTRODUCTION The pursuit of nanotechnology comprises a wide variety of disciplines: chemistry, physics, mechanical engineering, materials science, molecular biology, and computer science. In order to the miniaturization of integrated circuits well into the present century, it is likely that present day, nano-scale or nano electronic device designs will be replaced with new designs for devices that take advantage of the quantum mechanical effects that dominate on the much smaller nanometer scale .

Nanotechnology is often referred to as general purpose technology. That is because in its mature form it will have significant impact on almost all industries and all areas of society. It offers better built, longer lasting, cleaner, safer and smarter products for the home, for ammunition, for medicine and for industries for ages. These properties of nanotechnology have been made use of in solar cells. Solar energy is really an abundant source that is renewable and pollution free. This form of energy has very wide applications ranging from small household items, calculators to larger things like two wheelers, cars etc. they make use of solar cell that coverts the energy from the sun into required form. Department of ECE, sir MVIT

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It is expected that the global energy demand will double within the next 50 years. Fossil fuels,

however, are running out and are held responsible for the increased concentration of carbon dioxide in the earth’s atmosphere. Hence, developing environmentally friendly, renewable energy is one of the challenges to society in the 21st century. One of the renewable energy technologies is photovoltaics (PV), the technology that directly converts daylight into electricity. PV is one of the fastest growing of all the renewable energy technologies, in fact, it is one of the fastest growing industries at present. Solar cell manufacturing based on the technology of crystalline, silicon devices is growing by approximately 40% per year and this growth rate is increasing. This has been realized mainly by special market implementation programs and other government grants to encourage a substantial use of the current PV technologies based on silicon. Unfortunately, financial support by governments is under constant pressure. At present, the active materials used for the fabrication of solar cells are mainly inorganic materials, such as silicon (Si), gallium-arsenide (GaAs), cadmium-telluride (CdTe), and cadmium-indium-selenide (CIS). The power conversion efficiency for these solar cells varies from 8 to 29% . With regard to the technology used, these solar cells can be divided into two classes. The crystalline solar cells or silicon solar cells are made of either (mono- or poly-) crystalline silicon or GaAs. About 85% of the PV market is shared by these crystalline solar cells. Amorphous silicon, CdTe, and CI(G)S are more recent thin-film technologies.

Current solar power technology has little chance to compete with fossil fuels or large electric grids. Today’s solar cells are simply not efficient enough and are currently too expensive to manufacture for large-scale electricity generation. However, potential advancements in nanotechnology may open the door to the production of cheaper and slightly more efficient solar cells. Scientists have invented a plastic solar cell that can turn the sun's power into electrical energy, even on a cloudy day. The plastic material uses nanotechnology and contains the first solar cells able to harness the sun's invisible, infrared rays.

Department of ECE, sir MVIT

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CHAPTER 2

CONVENTIONAL SOLAR CELL 2.1 What is a solar cell? A solar cell (photovoltaic cell or photoelectric cell) is a solid state electrical device that converts the energy of light directly into electricity by the photovoltaic effect. The energy of light is electromagnetic fields, which in turn can make a current of electrons flow. Assemblies of solar cells are used to make solar modules which are used to capture energy from sunlight. When multiple modules are assembled together (such as prior to installation on a polemounted tracker system), the resulting integrated group of modules all oriented in one plane is referred as a solar panel. The electrical energy generated from solar modules, is an example of solar energy. Photovoltaics is the field of technology and research related to the practical application of photovoltaic cells in producing electricity from light, though it is often used specifically to refer to the generation of electricity from sunlight. Cells are described as photovoltaic cells when the light source is not necessarily sunlight. These are used for detecting light or other electromagnetic radiation near the visible range, for example infrared detectors, or measurement of light intensity.


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2.2 HISTORY AND DEVELOPMENT OF SOLAR CELL TECHNOLOGY The development of solar cell technology began with the 1839 research of French physicist Antoine-César Becquerel. Becquerel observed the photovoltaic effect while experimenting with a solid electrode in an electrolyte solution when he saw a voltage develop when light fell upon the electrode. The major events are discussed briefly below, and other milestones can be accessed by clicking on the image shown below. 

Charles Fritts - First Solar Cell: The first genuine solar cell was built around 1883 by Charles Fritts, who used junctions formed by coating selenium (a semiconductor) with an extremely thin layer of gold. The device was only about 1 percent efficient.



Albert Einstein - Photoelectric Effect: Albert Einstein explained the photoelectric effect in 1905 for which he received the Nobel Prize in Physics in 1921.



Russell Ohl - Silicon Solar Cell: Early solar cells, however, had energy conversion efficiencies of under one percent. In 1941, the silicon solar cell was invented by Russell Ohl.

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Gerald Pearson, Calvin Fuller and Daryl Chapin - Efficient Solar Cells: In 1954, three American researchers, Gerald Pearson, Calvin Fuller and Daryl Chapin, designed a silicon solar cell capable of a six percent energy conversion efficiency with direct sunlight. They created the first solar panels. Bell Laboratories in New York announced the prototype manufacture of a new solar battery. Bell had funded the research. The first public service trial of the Bell Solar Battery began with a telephone carrier system (Americus, Georgia) on October 4 1955.

CHAPTER 3

Generations of Solar Cells 3.1 First Generation: Crystalline Silicon Solar Cell Technology First generation solar cells are the larger, silicon-based photovoltaic cells. Silicon's ability to remain a semiconductor at higher temperatures has made it a highly attractive raw material for solar panels. Silicon's abundance, however, does not ease the challenges of harvesting and processing it into a usable material for microchips and silicon panels. Solar cells, use silicon Department of ECE, sir MVIT

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wafers consisting of Silicon or Germanium that are doped with Phosphorus and Boron in a pnjunction. Silicon cells have a quite high efficiency, but very pure silicon is needed, and due to the energy-requiring process, the price is high compared to the power output. Crystalline Silicon Solar Cells dominate 80-90% of solar cell market due to their high efficiency, despite their high manufacturing costs

3.2 Second Generation: Thin Film Solar Cell Technology Second generation solar cell, also known as thin-film solar cell (TFSC) or thin-film photovoltaic cell (TFPV), is made by depositing one or more thin layers (thin films) of photovoltaic material on a substrate. They are significantly cheaper to produce than first generation cells but have lower efficiencies. The great advantage of thin-film solar cells, along with low cost, is their flexibility and versatility to be used in varied environments. This has led to aesthetically pleasing solar innovations such as solar shingles, solar glass and solar panels that can be rolled out onto a roof or other surface. The most successful second generation materials have been cadmium telluride (CdTe), copper indium gallium selenide(CIGS), amorphous silicon and micro amorphous silicon. The thickness range of such a layer is wide and varies from a few nanometers to tens of micrometers. These materials are applied in a thin film to a supporting substrate such as glass or ceramics reducing material mass and therefore costs. It is predicted that second generation cells will dominate the residential solar market.

3.3 Third Generation: Dye-Sensitized Solar Cell Technology The electrochemical dye solar cell was invented in 1988 by Professor Graetzel of Lausanne Polytechnique, in Switzerland. The "Graetzel" dye cell uses dye molecules adsorbed in nanocrystalline oxide semiconductors, such as TiO2, to collect sunlight. Dye cells employ relatively inexpensive materials such as glass, Titania powder, and carbon powder. Graetzel's cell is composed of a porous layer of titanium dioxide nanoparticles, covered with a molecular dye that absorbs sunlight, like the chlorophyll does in green leaves. Third generation solar cells are the cutting edge of solar technology. These solar cells can exceed the theoretical solar conversion efficiency limit for a single energy threshold material. Current research is targeting conversion efficiencies of 30-60% while retaining low cost materials and manufacturing techniques.


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Chapter 4

HOW DO SOLAR CELLS WORK? Solar cells, which largely are made from crystalline silicon work on the principle of Photoelectric Effect that this semiconductor exhibits. Silicon in its purest form- Intrinsic Siliconis doped with a dopant impurity to yield Extrinsic Silicon of desired characteristic (p-type or ntype Silicon). Working of Solar cells can thus be based on crystalline structure of Intrinsic and Extrinsic Silicon. When p and n type silicon combine they result in formation of potential barrier. These and more are discussed below.

4.1 Pure Silicon (Intrinsic) Crystalline Structure Silicon has some special chemical properties, especially in its crystalline form. An atom of silicon has 14 electrons, arranged in three different shells. The first two shells- which hold two and eight electrons respectively- are completely full. The outer shell, however, is only half full with just four electrons (Valence electrons). A silicon atom will always look for ways to fill up its last shell, and to do this, it will share electrons with four nearby atoms. It's like each atom holds hands with its neighbours, except that in this case, each atom has four hands joined to four neighbours. That's what forms the crystalline structure. The only problem is that pure crystalline silicon is a poor conductor of electricity because none of its electrons are free to move about, unlike the electrons in more optimum conductors like copper


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4.2 Impurity Added Silicon (Extrinsic): P-type and N-type Semiconductors Extrinsic silicon in a solar cell has added impurity atoms purposefully mixed in with the silicon atoms, maybe one for every million silicon atoms. Phosphorous has five electrons in its outer shell. It bonds with its silicon neighbour atoms having valence of 4, but in a sense, the phosphorous has one electron that doesn't have anyone to bond with. It doesn't form part of a bond, but there is a positive proton in the phosphorous nucleus holding it in place. When energy is added to pure silicon, in the form of heat, it causes a few electrons to break free of their bonds and leave their atoms. A hole is left behind in each case. These electrons, called free carriers, then wander randomly around the crystalline lattice looking for another hole to fall into and carry an electrical current. In Phosphorous-doped Silicon, it takes a lot less energy to knock loose one of "extra" phosphorous electrons because they aren't tied up in a bond with any neighbouring atoms. As a result, most of these electrons break free, and release a lot more free carriers than in pure silicon. The process of adding impurities on purpose is called doping, and when doped with phosphorous, the resulting silicon is called N-type ("n" for negative) because of the prevalence of free electrons. N-type doped silicon is a much better conductor than pure silicon.The other part of a typical solar cell is doped with the element boron, which has only three electrons in its outer shell instead of four, to become P-type silicon. Instead of having free electrons, P-type ("p" for positive) has free openings and carries the opposite (positive) charge

4.3 Formation of Potential Barrier and Photoelectric Effect The electric field is formed when the N-type and P-type silicon come into contact. Suddenly, the free electrons on the N side combine the openings on the P side. Right at the junction, they combine and form something of a barrier, making it harder and harder for electrons on the N side to cross over to the P side (called POTENTIAL BARRIER). Eventually, equilibrium is reached, and an electric field separating the two sides is set up. This electric field acts as a diode, allowing (and even pushing) electrons to flow from the P side to the N side, but not the other way around. It's like a hill -- electrons can easily go down the hill (to the N side), but can't climb it (to the P side).


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When light, in the form of photons, hits solar cell, its energy breaks apart electron-hole pairs(Photoelectric effect). Each photon with enough energy will normally free exactly one electron, resulting in a free hole as well. If this happens close enough to the electric field, or if free electron and free hole happen to wander into its range of influence, the field will send the electron to the N side and the hole to the P side. This causes further disruption of electrical neutrality, and if an external current path is provided, electrons will flow through the path to the P side to unite with holes that the electric field sent there, doing work for us along the way. The electron flow provides the current, and the cell's electric field causes a voltage. Silicon is very shiny material, which can send photons bouncing away before energizing the electrons, so an antireflective coating is applied to reduce those losses. The final step is to install something that will protect the cell from the external elements- often a glass cover plate. PV modules are generally made by connecting several individual cells together to achieve useful levels of voltage and current, and putting them in a sturdy frame complete with positive and negative terminals.


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CHAPTER 5

INFRARED PLASTIC SOLAR CELL Scientists have invented a plastic solar cell that can turn the suns power into electric

energy

even on a cloudy day.

Plastic solar cells are not new .But existing materials are only able to harness the sun’s visible light. While half of the sun’s power lies in the visible spectrum, the other half lies in the infrared spectrum. The new material is first plastic compound that is able to harness infrared portion. Every warm body emits heat. This heat is emitted even by man and by animals, even when it is dark outside. The plastic material uses nanotechnology and contains the 1stgeneration solar cells that can harness the sun’s invisible infrared rays. This breakthrough made us to believe that plastic solar cells could one day become more efficient than the current solar cell. The researchers combined specially designed nano particles called quantum dots with a polymer to make the plastic that can detect energy in the infrared.


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With further advances the new PLASTIC SOLAR CELL could allow up to 30% of sun’s radiant energy to be harnessed completely when compared to only 6% in today plastic best plastic solar cells.

A large amount of sun’s energy could be harnessed through solar farms and used to power all our energy needs. This could potentially displace other source of electrical production that produce green house gases like coal. Solar energy reaching the earth is 10000 times than what we consume. If we could cover 0.1% of the earth’s surface with the solar farms we could replace all our energy habits with a source of power which is clear and renewable. The first crude solar cells have achieved efficiencies of today’s standard commercial photovoltaic’s the best solar cell, which are very expensive semiconductor laminates convert at most, 35% of the sun’s energy into electricity.

5.1 WORKING OF PLASTIC SOLAR CELL The solar cell created is actually a hybrid, comprised of tiny nanorods dispersed in an organic polymer or plastic. A layer only 200 nanometers thick is sandwiched between electrodes and can produce at present about .7 volts. The electrode layers and nanorods /polymer layers could be applied in separate coats, making production fairly easy. And unlike today’s semiconductorbased photovoltaic devices, plastic solar cells can be manufactured in solution in a beaker without the need for clean rooms or vacuum chambers.


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The technology takes advantage of recent advances in nanotechnology specifically the production of nanocrystals and nanorods. These are chemically pure clusters of 100 to 100000 atoms with dimensions of the order of a nanometer, or a billionth of a meter. Because of their small size, they exhibit unusual and interesting properties governed by quantum mechanics, such as the absorption of different colors of light depending upon their size. Nanorods were made of a reliable size out of cadmium selenide, a semi conducting material. Nanorods are manufactured in a beaker containing cadmium selenide, aiming for rods of diameter-7 nanometers to absorb as much sunlight as possible. The length of the nanorods may be approximately 60nanometers.Then the nanorods are mixed with a plastic semiconductor called p3ht-poly-(3-hexylthiophene) a transparent electrode is coated with the mixture. The thickness, 200 nanometers-a thousandth the thickness of a human hair-is a factor of 10 less than the micron-thickness of semiconductor solar cells. An aluminium coating acting as the back electrode completed the device. The nanorods act like wires. When they absorb light of a specific wavelength, they generate an electron plus an electron hole-a vacancy in the crystal that moves around just like an electron. The electron travels the length of the rod until it is collected by aluminium electrode. The hole is transferred to the plastic, which is known as a hole-carrier, and conveyed to the electrode, creating a current.


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CHAPTER 6

Quantum dots with built-in charge boost solar cell efficiency by 50%

(Left) A diagram of a quantum dot structure. (Center) A comparison of solar cells with different levels of doping. (Right) The 3D potential profile in quantum dot structures

For the past few years, researchers have been using quantum dots to increase the light absorption and overall efficiency of solar cells. Now, researchers have taken a step further, demonstrating that quantum dots with a built-in electric charge can increase the efficiency of InAs/GaAs quantum dot solar cells by 50% or more. The researchers, Kimberly Sablon and John W. Little (US Army Research Laboratory in Adelphi, Maryland), Vladimir Mitin, Andrei Sergeev, and Nizami Vagidov (University of Buffalo in Buffalo, New York), and Kitt Reinhardt (AFOSR/NE in Arlington, Virginia) have published their study on the increased solar cell efficiency in a recent issue of Nano letters. In their study, the researchers studied heterostructure solar cells with InAs/GaAs quantum dots. As photovoltaic materials, the quantum dots allow for harvesting of Department of ECE, sir MVIT

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the infrared radiation to convert it into electric energy. However, the quantum dots also enhance the recombination of photocarriers and decrease the photocurrent. For this reason, up to now the

improvement of photovoltaic efficiency due to quantum dots has been limited by several percent. Here, the researchers have proposed to charge quantum dots by using selective interdot doping. In their experiments, the researchers compared doping levels of 2, 3, and 6 additional electrons per quantum dot, which resulted in photovoltaic efficiency increases of 4.5%, 30%, and 50%, respectively, compared to an undoped solar cell. For the 6-electron doping level, that 50% increase corresponds to an overall efficiency increase from 9.3% (for undoped solar cells) to 14%. The researchers attributed this radical improvement of the photovoltaic efficiency to two basic effects. First, the built-in-dot charge induces various transitions of the electrons and enhances harvesting of the infrared radiation. Second, the built-in-dot charge creates potential barriers around dots and these barriers suppress capture processes for electrons and do not allow them to return back into the dots. The effect of potential barriers has been previously used by the researchers to improve the sensitivity of infrared detectors. In addition, the researchers predict that further increasing the doping level will lead to an even stronger efficiency enhancement, since there was no evidence of saturation. In the future, the researchers plan to further investigate how these effects influence each other at higher doping levels. They predict that further increasing the doping level and radiation intensity will lead to an even stronger efficiency enhancement, since there was no evidence of saturation. “The methodology and principles developed during this research are applicable to a number of photovoltaic devices with quantum dots and nanocrystals, such as polymer plastic cells and dyesensitized porous metal oxide Gratzel cells,” Dr. Sergeev told PhysOrg.com. “Effective harvesting and conversion of infrared radiation due to optimized electron-hole kinetics in structures with quantum dots and nanocrystals will lead to potential breakthroughs in the area of solar energy conversion.”


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CHAPTER 7

Quantum dot Photovoltaic Quantum dots grown using colloidal synthesis can be dried into thin films. The application of the colloidal solution containing the polymer to a metal nano mask consisting of an array of submicron holes allows near-field detection of any quantum dots that lie directly under a hole. While the distribution of quantum dots in the film is random, variation of the quantum dot density is easily achieved by dilution, enabling an optimum density for the mask hole size to be found. If two or more quantum dots lie under a hole in the mask, they will be detected spectroscopic ally. The use of a metal nano mask for this near-field detection enables the mask to be charged, which in turn will apply an electric field to the quantum dots under observation. The application of such an electric field will provide a means of continuously varying the coupling between quantum dots, which is effectively the J-gate operation. The possibility of quantum dots as dye replacements in dye sensitized solar cells has been theoretically suggested. The size selective growth characteristic of quantum dots allows absorption tuning. Potentially PbS could span the whole spectrum. Secondly emission at longer wavelength is observed which could be utilized in a second absorbing layer.


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7.1 Quantum Dot Sentized Titania Solar Cell

We exploit the photovoltaic properties of quantum dots with plans to use them as dye replacements in dye sensitized cells such as those designed by Gratzel. An advantage of QD`s is that they are more stable than dyes of their crystalline nature. Also dyes have low efficiency due to re-absorption whereas qd emission is red shifted away from absorption.

7.2 Cell Operation

Electron transport in the quantum dot sensitised titania solar cell. A photon excites an electron in QD which is swept away by the in-built electric field into the TiO2/SnO2 electrode and conducted around the circuit. At the Pt/SnO3 electrode the electron is transferred into the electrolyte which acts as an electron shuttle to the QD. Department of ECE, sir MVIT

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CHAPTER 8

Konarka's Technologies Konarka is focused on the development and advancement of nano-enabled polymer photovoltaic materials that are lightweight, flexible and more versatile than traditional solar materials. Konarka’s technology represents a new breed of coatable, plastic, flexible photovoltaic material that can be used in many applications where traditional photovoltaic cannot compete. Konarka has provided that breakthrough by developing photovoltaic cells on lower cost, lightweight, flexible plastic substrates rather than on glass. Konarka’s photovoltaic technology can utilize a wider range of the light spectrum than conventional solar cells, visible and invisible light sources, not just sunlight, can be used to generate power. Konarka’s nanomaterials absorb sunlight and indoor light. This light energy travels through the electrically active materials and a series of electrodes and is converted into electrical energy. Konarka’s unique photo reactive materials can be printed or coated inexpensively onto flexible substrates using roll-to-roll manufacturing, similar to how newspaper is printed on large rolls of paper. Just as newsprint can include text, images, and a variety of colors, Konarka’s photovoltaic materials can include a range of colors and patterns. In addition, Konarka’s materials can be produced with varying degrees of translucency so they can be customized for use in new products and markets. Konarka’s manufacturing process enables production to scale easily and results in significantly reduced costs over previous generations of solar cells. The process is environmentfriendly and does not expose the materials to harmful high temperatures. Another significant advantage is that it does not require the invention of a new factory to do this – instead it can use existing coating and printing machines and technologies. Finally, solar cells can be produced and used virtually anywhere, enabling production even in regions where supporting infrastructure is generally thought to be insufficient. solar power is four to ten times more costly to produce than electricity from conventional power plants.For decades, solar-cell researchers have tried to develop cheaper alternatives to silicon. The problem has been efficiency: other materials just don’t generate enough electricity.


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But Siemens’s achievement earlier this year of the highest efficiency to date in plastic solar cells could change that. The Siemens design combined two of the most important advances in materials science in the past 30 years: electrically conducting polymers and buckyballs. The idea of combining these materials to capture solar power first gained credence in the early 1990s, when physicists Sariciftci and Alan Heeger at the University of California, Santa Barbara, created primitive photovoltaic devices by pouring a solution of conducting plastic and buckyballs onto a glass plate, spinning the plate to spread the solution into a film, and sandwiching the film between electrodes. The conducting polymer absorbed photons, kicking off electrons that were then attracted by the buckyballs and routed to an electrode. In short, the film acted like a solar cell.Originally, the power output was meager (less than 1 percent of the energy of incoming sunlight). But the principle of the printable solar cell was proved: you could layer a photovoltaic material on a surface and make it work without complex preparations.


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CHAPTER 9

IMPROVEMENTS Some of the obvious improvements include better light collection and concentration, which already are employed in commercial solar cells. Significant improvements can be made in the plastic, nanorods mix, too, ideally packing the nanorods closer together, perpendicular to the electrodes, using minimal polymer, or even none-the nanorods would transfer their electrons more directly to the electrode. In their first-generation solar cells, the nanorods are jumbled up in the polymer, leading to losses of current via electron-hole recombination and thus lower efficiency. They also hope to tune the nanorods to absorb different colors to span the spectrum of sunlight. An eventual solar cell has three layers each made of nanorods that absorb at different wavelength.

CHAPTER 10

APPLICATIONS 1. Silicon possesses some nanoscale properties. This is being exploited in the development of a super thin disposable solar panel poster which could offer the rural dwellers a cheap and an alternative source of power. Most people living in remote areas are not linked to national electricity grid and use batteries or run their own generator to supply their power needs. Disposal solar panels can be made in thin sheets with about 6-10 sheets stacked together and made into a poster can help them to some extent in this regard. This poster could be mounted behind a window or attached to a cabinet

2. Like paint the compound can also be sprayed onto other materials and used as portable electricity. Department of ECE, sir MVIT

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3. Any chip coated in the material could power cell phone or other wireless devices.

4. A hydrogen powered car painted with the film could potentially convert energy into electricity to continually recharge the car’s battery.


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5. One day solar farms consisting

of plastic materials could be rolled across deserts to

generate enough clear energy to supply the entire planet’s power needs

CHAPTER 11

ADVANTAGES Plastic solar cells are quite a lot useful in the coming future. This is because of the

large

number of advantages it has got. Some of the major advantages are: 1. They are considered to be 30% more efficient when compared to conventional solar cells. 2. They are more efficient and more practical in application. 3. Traditional solar cells are bulky panels. This is very compact. 4. Conventional solar cells are only used for large applications with big budgets. But the plastic solar cells are feasible as they can be even sewn into fabric- thus having vast applications. 5. Flexible, roller processed solar cells have the potential to turn the sun’s power into a clean, green, consistent source of energy.


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CHAPTER 12

DISADVANTAGES 1. The biggest problem with this is cost effectiveness. But that could change with new material. But chemists have found a way to make cheap plastic solar cells flexible enough to paint onto any surface and potentially able to provide electricity for wearable electronics or other low power devices. 2. Relatively shorter life span when continuously exposed to sunlight. 3. Could possibly require higher maintenance and constant monitoring.

CHAPTER 13

CONCLUSION Plastic solar cells help in exploiting the infrared radiation from the sun’s rays. They are more effective when compared to the conventional solar cell. The major advantage they enjoy is that they can even work on cloudy days, which is not possible in the former. They are more compact and less bulky. Though at present, cost is a major drawback, it is bound be solved in the near future as scientists are working in that direction. As explained earlier, if the solar farms can become a reality, it could possibly solve the planets problem of depending too much on the fossil fuels, without a chance of even polluting the environment.


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REFERENCES 1. Nanomaterials: Synthesis, Properties and Applications: Edelstein, A. S., Cammarata R. C., Eds.; Institute of Physics Publishing: Bristol and Philadelphia, 1996. 2. The Coming Era of Nanotechnology; 1987. Drexler, K. Eric, Doubleday; New York 3. A gentle introduction to the next big idea-Mark A. Ratner, Daniel Ratner. 4. Introduction to nanotechnology- Charles P Poole, Frank J Owens 5. The clean power revolution- Troy Helming 6. Solar energy-fundamentals, design, modeling, applications- G.N. Tiwari 7. Thin film solar cells next generation photovoltaic and its application- Y Hamakawa


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Report of Infrared plastic solar cell

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