Solar Photovoltaic Technology

Abstract

There is all around focus on the development of renewable energy due to energy security, climate change and energy access. Solar photovoltaic deals with conversion of sunlight into electricity. Understanding the available energy resources at Earth’s surface that can be used for this conversion is important. The single- and multi-crystalline silicon solar cells dominate the present PV market and occupy >85% of it. Advancements are continuously being made and efficiency of the most widely used cells using c-Si cells now touching up to 20%. Higher efficiency cells use III–V compound semiconductors. Commercial efficiency of more than 30% is now routinely achieved using high-efficiency multi-junction (MJ) III–V cells. Due to cost consideration, these cells are primarily being used in space. Concentrated Photovoltaic (CPV) using high-efficiency MJ cells are used in terrestrial application. Thin-film solar cell is relatively new technology and now occupies about 10% of PV market. The present conversion efficiencies of a-Si thin film solar cells are 8–10% (stabilized) and that of micromorph 9–11% (stabilized) at the production level. Amongst the compound semiconductor, thin-film solar cells CdTe are being produced on mass scale. The conversion efficiency is about 10%. For CIGS the production technology is not yet fully matured. There are several new types of solar cell technologies attracting attention. Dye-sensitized solar cell (DSSC) mimics photosynthesis process. The efficiency achieved is 15–16% in the laboratory scale. However, stability is a problem which is standing in the way of its commercial production. Organic and polymer-based solar cells have not been able to make much progress in terms of efficiency and stability. The other important R&D activities which are going to enhance the conversion efficiencies of solar cells are based on better light management so that current from the cell goes up. For this nanotechnology involving nanostructures are being used.