In this paper porous silicon sample that can be used as a photodetector was prepared at fixed etching time of 15min and different etching current density (15, 17, 19 and 21) mA/cm 2 . Electrical properties of Al / PSi / p-Si /Al photodetector were studied. We found that the I-V characteristics dependence of the etching current density relates to the PSi pores development, where the pore diameter in PSi structure might get enlarged due to the enhancement of the etching current density. The ideality factor ranges around (6.8-4.2) while the barrier height decreased with the increasing etching current density and the etching time as the interface layer between PSi/c-Si has large amount of pinning. Then the C-V characteristics of the sandwich structure are described. When the etching current densities are increased, it reduces the capacitance of the PSi layer. It thus increases the thickness of the depletion region which in turn results in development of built-in potential.

This study presents porous silicon (PSi) samples preparation by electrochemical etching method of p type silicon wafers of 100 degree orientation with different etching time (15, 17, 19, 21)min and with fixed electrolyte solution (40% HF: 99.98% CH 3 OH) (1:1). The optical property is described by PhotoLuminescence (PL). The PL measurements of PSi samples show that the energy gap increased after the etching process, and all samples exhibit blue shift with the increasing PL intensity.

In this study, Porous Silicon (PSi) samples are prepared by electrochemical etching method of p-type silicon wafers of 100 orientation with different etching current densities (15, 17, 19 and 21 mAcmG 2) for 15 min etching time and different etching times (15, 17, 19 and 21 min) for 15 mAcmG 2 etching current density with fixed electrolyte solution (40% HF: 99.98% CH 3 OH) (1:1). The photovoltaic properties is described by spectral Responsivity (R λ) and specific Detectivity (D λ*). The photovoltaic measurements of PSi samples showed that the increasing in both current densities and etching times caused a blue shift in the peak of the responsivity and the maximum responsivity 0.41 A/W appears at 800 nm despite the fact that this region is far from the cutoff wavelength in order to coincide with mass action law.