Application of stain-etched porous silicon in light emitting diodes and solar cells

Porous silicon/c-Si heterostructures have been formed by the method of stai n etching. The properties of light emitting diodes (LED) and solar cells ha ve been studied. The transport mechanism of the diode has been investigated from the current-voltage characteristics measured at different temperature s (296-380 K). A model based on multi-step tunneling of carriers at reverse and low forward bias ( < 1 V) and on held tunneling across a narrow barrie r at higher forward bias (> 1.5 V) is proposed for the LLD. In the case of the solar cells the porous silicon is formed in between the fingers of the front grid contact. Application of porous silicon in solar cells results in an increase of the short-circuit current and efficiency of the cells by ab out 30%. (C) 1999 Elsevier Science B.V. All rights reserved.