Research Information System
Solid State Crystals in Optoelectronics and Semiconductor Technology, Zakopane, Poland, 07 October 1996, vol.3179, pp.33-40, (Full Text)
Photovoltaic effects from porous silicon (PS) based devices fabricated with electro-chemical etching processes have been investigated. Contact to the PS were made by bonding a small region of Al on a semi-transparent Au film. The structure of the uncoated porous layers were studied by SEM. Two levels of porosity were observed in n-type UV- and VIS-PS, surface etched features a few nanometres in diameter and macropores running deep in the bulk Si. Only nanopores were seen in p-type PS. The photovoltaic effects from the combination of the Au / porous Si junction and the PS / bulk Si heterojunction were observed under white-light of different intensity. The I-V characteristics of several PS based photovoltaic devices have been measured using a calibrated source. Photovoltages of the differently prepared n-type VIS-PS devices have been measured as a function of excitation energy. The polarities of photovoltage for both types of devices were found to be the same. P-type devices shows different I-V characteristics, depending on anodisation current, all n-type PV devices present similar I-V characteristics.