Novel technique for preparation of porous silicon

摘要

Porous silicon (PS) was prepared by hydrothermal treatment of silicon in LiF-containing nitric acid solu- tion. Scanning tunneling microscope (STM) studies show that the PS layers were uniform, and consisted of columns with cross-sectional diameters significantly less than 10 nm. The luminescence measurement revealed that the wave- length of the photoluminescence (PL) peaks was at 690 nm, which was somewhat shifted toward the higher energy side as compared with that of the porous silicon obtained by anodic etching.