Nowadays, thin-film solar cells potentially offer a suitable technology for solving the energy production problem with an environmentally friendly method. Besides, thin film technologies show advantages over their bulk-semiconductor counterparts due to their lighter weight, flexible shape and device fabrication schemes and low cost in large-scale industrial production. Although many books currently exist on general concepts of PV materials and devices, few are offering a comprehensive overview of the fast development in thin film Cu(In, Ga)Se2-based solar cells. "Key Developments in CuInGaSe2 Thin Film Solar Cell" would provide an international perspective on the latest research on this topic. It presents a wide range of scientific and technological aspects on basic properties and device physics of high-efficiency CIGS solar cells from the last research frontier point of view. The book was designed for photovoltaic researchers and scientists, students and engineers, with the mission to provide knowledge of the mechanisms, materials, devices, and applications of CIGS-based technology necessary to develop cheaper and cleaner renewable energy in the coming years.

"You, 0 Sun, are the eye of the world You are the soul of all embodied beings You are the source of all creatures You are the discipline of all engaged in work" - Translated from Mahabharata 3rd Century BC Today, energy is the lifeline and status symbol of "civilized" societies. All nations have therefore embarked upon Research and Development pro grams of varying magnitudes to explore and effectively utilize renewable sources of energy. Albeit a low-grade energy with large temporal and spatial variations, solar energy is abundant, cheap, clean, and renewable, and thus presents a very attractive alternative source. The direct conver sion of solar energy to electricity (photovoltaic effect) via devices called solar cells has already become an established frontier area of science and technology. Born out of necessity for remote area applications, the first commercially manufactured solar cells - single-crystal silicon and thin film CdS/Cu2S - were available well over 20 years ago. Indeed, all space vehicles today are powered by silicon solar cells. But large-scale terrestrial applications of solar cells still await major breakthroughs in terms of discovering new and radical concepts in solar cell device structures, utilizing relatively more abundant, cheap, and even exotic materials, and inventing simpler and less energy intensive fabrication processes. No doubt, this extraordinary challenge in R/D has led to a virtual explosion of activities in the field of photovoltaics in the last several years.

The fundamental concept of the book is to explain how to make thin film solar cells from the abundant solar energy materials by low cost. The proper and optimized growth conditions are very essential while sandwiching thin films to make solar cell otherwise secondary phases play a role to undermine the working function of solar cells. The book illustrates growth and characterization of Cu2ZnSn(S1-xSex)4 thin film absorbers and their solar cells. The fabrication process of absorber layers by either vacuum or non-vacuum process is readily elaborated in the book, which helps for further development of cells. The characterization analyses such as XPS, XRD, SEM, AFM etc., lead to tailor the physical properties of the absorber layers to fit well for the solar cells. The role of secondary phases such as ZnS, Cu2-xS,SnS etc., which are determined by XPS, XRD or Raman, in the absorber layers is promptly discussed. The optical spectroscopy analysis, which finds band gap, optical constants of the films, is mentioned in the book. The electrical properties of the absorbers deal the influence of substrates, growth temperature, impurities, secondary phases etc. The low temperature I-V and C-V measurements of Cu2ZnSn(S1-xSex)4 thin film solar cells are clearly described. The solar cell parameters such as efficiency, fill factor, series resistance, parallel resistance provide handful information to understand the mechanism of physics of thin film solar cells in the book. The band structure, which supports to adjust interface states at the p-n junction of the solar cells is given. On the other hand the role of window layers with the solar cells is discussed. The simulation of theoretical efficiency of Cu2ZnSn(S1-xSex)4 thin film solar cells explains how much efficiency can be experimentally extracted from the cells. - One of the first books exploring how to conduct research on thin film solar cells, including reducing costs - Detailed instructions on conducting research

Cu(In1-xGax)Se2 Based Thin Film Solar Cells provides valuable contents about the fabrication and characterization of chalcopyrite Cu(In1-xGax)Se2 based thin film solar cells and modules. The growth of chalcopyrite Cu(In1-xGax)(S1-ySey)2 absorbers, buffers, window layers, antireflection coatings, and finally metallic grids, which are the sole components of solar cells, is clearly illustrated. The absorber, which contains multiple elements, segregates secondary phases if the growth conditions are not well optimized i.e., the main drawback in the fabrication of solar cells. More importantly the solutions for the growth of thin films are given in detail. The properties of all the individual layers and single crystals including solar cells analyzed by different characterization techniques such as SEM, AFM, XPS, AES, TEM, XRD, optical, photoluminescence, and Raman spectroscopy are explicitly demonstrated. The electrical analyses such as conductivities, Hall mobilities, deep level transient spectroscopy measurements etc., provide a broad picture to understand thin films or single crystals and their solar cells. The book clearly explains the working principle of energy conversion from solar to electrical with basic sciences for the chalcopyrite based thin film solar cells. Also, it demonstrates important criteria on how to enhance efficiency of the solar cells and modules. The effect of environmental factors such as temperature, humidity, aging etc., on the devices is mentioned by citing several examples. - Illustrates a number of growth techniques to prepare thin film layers for solar cells - Discusses characterization techniques such as XRD, TEM, XPS, AFM, SEM, PL, CL, Optical measurements, and Electrical measurements - Includes I-V, C-V measurements illustrations - Provides analysis of solar cell efficiency - Presents current trends in thin film solar cells research and marketing

Electricity power is normally generated by burning fossil fuels, having detrimental impacts on the environment and will be depleted. One of the most appropriate ways to solve the foreseeable world's energy crisis is to utilize the power of the sun. Solar cells, using photovoltaic effect, are of wide interest as they can convert solar energy to electricity. Chalcopyrite based thin-film solar cell is considered as the low-cost and high-efficiency solar cells. One of the most important chalcopyrite compounds for photovoltaic application is Cu(In, Ga)Se2. Fabricating the solar cells on flexible substrates is intriguing, as it can be applied to the roll-to-roll process with the ability to reduce production cost of the solar cells. Consequently, the purpose of the book is to provide the overview for accomplishing the good physical properties and suitable double [Ga]/([Ga]+[In])-grading profiles of Cu(In, Ga)Se2 absorbers on flexible stainless steel substrates for the thin-film solar cells with high conversion efficiency (>15%