The Surface Photovoltaic and Photoluminescent Evolution of a Silicon Nanoporous Pillar Array for Different Etching Times

A series of silicon nanoporous pillar array(Si-NPA)samples are prepared with different times of hydrothermal etching,and their surface morphologies are characterized.A systematic study on the evolution trend of the surface photovoltage and photoluminescence spectra discloses that the adoption of a prolonged etching time will increase the native degree of oxidation and decrease the interfacial states density localized in the SiO𝑥matrix.These results might be helpful for designing Si-NPA-based semiconductor nanosystems with optimized physical properties.