Porous silicon application in solar cell technology

Possible and already realized applications of porous silicon (PS) layers in silicon solar cell technology are overviewed. Four main directions are marked for PS incorporation: a) heterojunction formation, b) light trapping, c) antireflection coating, and d) surface passivation. Standard PS preparation technique is discussed and a new one is proposed, applicable for large area devices. Optical and electric parameters of PS layers, obtained at different electrochemical etching conditions, are presented Experimental results of PS action are compared with calculations for light trapping and antireflection coating effects. Detailed study of possible passivation effect is given both for mono- and multicrystalline silicon solar cells. The obtained results show good perspectives for PS application in cheap and efficient silicon solar cell production.