Photovaltaic effect in MPS structure

In this paper, we report the recent results about photovoltaic effects in a metal (Al or Au) /porous silicon (MPS) structure. We have given the spectral response curves of the Schottky diode structures for the first time, and investigated the dependences of the open circuit voltage on the incident light intensity and the measurement temperature. The results obtained show that the Schottky junction between the metal and the porous silicon layer should be the principal source of the photovoltaic actions, while the heterojunction between the porous silicon layer and the silicon substrate could impede the transport of the forward current in this structures. It is also found that the open circuit voltage increases linearly with decreasing of temperature in the range of 300-120 K and the temperature coefficient is ∼2.0 mV/K and ∼2.8 mV/K for Au/PS and Al/PS diodes, respectively.