Variations of the optical characteristics of nano-, meso-, and macroporous silicon with time

摘要

Time variations in the composition and optical properties of porous silicon samples with different pore sizes are discussed. Substrate orientation, type of conduction, and composition of etching solution were varied to produce nano-, meso-, and macroporous silicon and multilayer porous structures. A correlation of the photoluminescence (PL) intensity of the samples after long-term storage in air and the intensity of the IR absorption band (616 cm(-1)) assigned to the Si-Si bonds is demonstrated. The nanoporous silicon exhibits the highest PL intensity after 120-day storage.