Paper Title
Technologies, Developments and Production of Photovoltaic Solar Cells and Photovoltaic Power Systems

Abstract
The various types of materials applied for photovoltaic solar cells includes mainly in the form of silicon (single crystal, multi-crystalline, amorphous silicon), cadmium-telluride, copper-indium-gallium-selenide, copper-indium-gallium-sulfide, Perovskite, dye sensitized, and organic are reviewed and characterized. The Performance of first generation solar cells (c-Si based) photovoltaic (PV) technology conversion efficiency lies in the range of 17 to 25% and predicts that the efficiency will reach a maximum of ~ 26.95 % by the year 2024. Multicrystalline silicon solar cell predicted to reach efficiency of 25%. price has been reduced by a factor of 250 over last twenty years (from ~ 76USD to ~ 0.3 USD); its market growth is expected to reach 100 GWP by 2020. In September 2017, the U.S. Department of Energy announced that the U.S. solar industry had achieved the 2020 utility-scale solar cost target of US $0.06/kWh. Thin film technology (second generation) has the cheaper cost, and can be considered as one of the promising technology for its attractive cost of energy. There are several semiconductor materials that are potential candidates for thin-film solar cells, namely: First: Hydrogenated amorphous silicon (a-Si:H) with best efficiency recorded was around 11%. Second: Cadmium telluride (CdTe), with the best efficiency of single cell recorded was 21% while CdTe based modules has been made the highest efficiency of 16.5%. Third: Copper indium gallium diselenide (CuInGaSe2=CIGS) paves the way for progress at the cell level (~ 25% efficiency), mini module (~ 21%) towards total area module efficiencies of 18%. There are several third generation concepts: Multi-junction solar cells, Concentrator photovoltaics, Spectral up and down conversion, Multi-exciton generation, Intermediate band-gap solar cells and Hot carrier solar cells. A maximum 38.8% efficiency is recorded for five junctions single cell, 11.2% for organic cell and around 10% for organic module. Over the last two decades, grid-connected solar photovoltaic (PV) systems have increased to one of the leading power generation capacity additions annually. In 2018, over 100 GW of new PV power capacity was added. Total installed PV power capacity was in excess of 500 GW at the end of 2018 Keywords - Efficiency, Photovoltaic, PV systems, Solar cell.