Abstract: The optical and electrical properties of ZnO/porous Si (PS) heterostructure are studied.The PS sample is formed by the anodization of a single-crystal Si wafer.ZnO films are then deposited on the PS substrate by pulsed laser deposition.White light formed by combining the red emission from the PS layers with the blue-green emission from the ZnO films is obtained.Due to the roughness of the PS surface,some cracks appear in the ZnO films,which can be seen from the SEM spectra.The I-V characteristics of the ZnO/PS heterostructure are different from those of the common diode,whose reverse current is not saturated.Based on the I-V characteristics,an energy band diagram is proposed.

Key words: white light emission, porous silicon, ZnO, photoluminescence, energy band diagram