Recent Developments in High- Efficiency PV Cells

Enormous progress has been made in recent years on a number of photovoltaic (PV) materials and devices in terms of conversion efficiencies. Ultrahigh-efficiency (>30%) PV cells have been fabricated from gallium arsenide (GaAs) and its ternary alloys such as gallium indium phosphide (GaInP2). The high-efficiency GaAsbased solar cells are being produced on a commercial scale, particularly for space applications. Efficiencies in the range of 18%–24% have been achieved in traditional silicon-based devices fabricated from both multicrystalline and single-crystal materials. Major advances in efficiency have also been made on various thin-film solar cells based on amorphous silicon (aSi:H), copper gallium indium diselenide (CIGS), and cadmium telluride materials. This paper gives a brief overview of the recent progress in PV cell efficiencies based on these materials and devices.