Studies Of Buffer Layers Of Cu(in, Ga)Se₂-based Solar Cell

Development of clean energy resources as an alternative to fossil fuels has become one of the important challenges for modern science and technology in the 21st century. Reduction of air pollution and preservation of the ecological systems of earth are main motivation factors behind these huge efforts. Some of the major contenders for the alternative clean resources are hydroelectric, tidal, nuclear and solar energy. But of all these renewable energy sources photovoltaics is the most promsing one as a future energy technology. The photovolltaic effect is the process of direct conversion of sunlight into electrical energy. The major advantage of these photovoltaics systems is that they tap an almost inexhaustible resource that is free of charge and available everywhere in the world.The main barrier impeding the expansion of the terrestrial application of photovoltaic is the high price of the solar cell modules. The reasons for these high costs are the high processing and material costs. A recent survey suggests that a further cost reduction to one fifth of the present level is a must for photovoltaics to match the conventional electricity price. One of the solutions to achieve a reduction in this cost is the development of thin film solar cells. This cost reduction is due to factors like lower material use, fewer and simper processing steps as compared to a traditional wafer based crystalline silicon solar cell. At present, research is done on the alloys of amorphous Silicon, CdTe, and Cu(In, Ga)Se₂ as major contenders for large scale production.The Cu(In, Ga)Se₂-based solar cell belongs to theâ… -â…¢-â…¥class of thin film solar cells, and has shown great promise for photovoltaic applications. But there are many issues of fabricating a large area, stable, high efficient CIGS module by scaleable, low-cost techniques on inexpensive substrates. Our project is to improve techniques of preparing solar cell materials, to increase performance of the devices and reduce system cost. ZnO and CdS thin film play most important role as window layers of CIGS solar cells. In our project, I prepared high quality ZnO thin film by using magnetron sputtering system and CdS thin film by a modified chemical bath deposition technique.