The Surface Photovoltage Mechanism of a Silicon Nanoporous Pillar Array

The surface photovoltage (SPV) mechanism of a silicon nanoporous pillar array (Si-NPA) is investigated by using SPV spectroscopy in different external electric fields. Through comparisons with the SPV spectrum of single crystal silicon (sc-Si), the silicon nano-crystallite (nc-Si)/SiO_x nanostructure of Si-NPA is proved to be capable of producing obvious SPV in the wavelength range 300–580 nm. The SPV for the sc-Si layer and the nc-Si/SiO_x nanostructure has shown certain contrary characters in different external electric fields. Through analysis, the localized states in the amorphous SiO_x matrix are believed to dominate the SPV for the nc-Si/SiO_x nanostructure.