Photoresponse of metal-porous silicon-silicon structure

In this article, we first review the potential applications of porous silicon (PS) in solar cell structures. Then we describe the fabrication of this material by electrochemical anodization method in hydrofluoric acid (HF) solution. The spectral responses of photovoltaic devices based on metal-PS-Si sandwich structures are presented. At room temperature, the photoresponse (photovoltage or photocurrent) of these devices has been measured by variation of the optical excitation energy. The highest photosensitivity (photocurrent) was found to be at a wavelength of 540 nm. The photoresponse of PS shows better results as compared to a Si solar cell. The contribution of the photovoltaic effects from the junctions of the metal-PS and from PS-Si heterojunction was observed for the visible wavelength range of light and under white light of different powers. Current-voltage (I-V) characteristics have been done in dark and room light. The results indicate that the sandwich structure has a diode barrier.