Multicrystalline silicon solar cells with porous silicon emitter

A review of the application of porous silicon (PS) in multicrystalline sili con solar cell processes is given, The different PS formation processes, st ructural and optical properties of PS are discussed from the viewpoint of p hotovoltaics. Special attention is given to the use of PS as an antireflect ion coating in simplified processing schemes and for simple selective emitt er processes as well as to its light trapping and surface passivating capab ilities. The optimization of a PS selective emitter formation results in a 14.1% efficiency me-Si cell processed without texturization, surface passiv ation or additional ARC deposition. The implementation of a PS selective em itter into an industrially compatible screenprinted solar cell process is m ade by both the chemical and electrochemical method of PS formation. Differ ent kinds of multicrystalline silicon materials and solar cell processes ar e used. An efficiency of 13.2% is achieved on a 25 cm(2) Inc-Si solar cell using the electrochemical technique while the efficiencies in between 12% a nd 13% are reached for very large (100-164 cm(2)) commercial me-Si cells wi th a PS emitter formed by chemical method. (C) 2000 Elsevier Science B.V. A ll rights reserved.