Improvement of current injection of porous silicon

n-i-p-n hydrogenated amorphous silicon (a-Si:H) layers were deposited onto porous silicon (PS) formed on p-type crystalline silicon (c-Si) by anodization and used to improve the current injection of a PS-based light-emitting diode (LED). The electroluminescence (EL) spectrum for the obtained PS-based LED with n-i-p-n a-Si:H layers showed the similar tendency as that of a photoluminescence (PL) signal for an as-anodized PS. The current conduction mechanisms of this PS-based LED were also studied.