Electrical behavior of double-sided metal/porous silicon structures for optoelectronic devices

Porous silicon (PS)-based devices consisting of a metal/PS/Si/PS/metal structure were investigated in this study for potential use in photodiodes and solar cells. The PS layers act as front antireflective coating for short wavelength light and back surface reflector/diffuser for high wavelength radiation. The PS layers were formed by the chemical etching of crystalline silicon. Different metals such as Au/Cr, W, Ta, WTi, Cr and Ti were sputter deposited onto both PS surfaces. The electrical behavior of the resulting devices was determined to ascertain the most appropriate metallic contact for the development of these optoelectronic devices.