Light-Induced Degradation and Recovery of Visible Photoluminescence in Porous Silicon

Abstract
We have investigated the light-induced degradation of visible photoluminescence (PL) and its recovery in porous silicon. It has been found that the exposure of the porous sample to UV and visible laser light results in the drastic quenching of the PL intensity. Furthermore, the PL intensity in the photodegraded sample is effectively recovered by annealing at low temperature up to 200°C, rather than by HF etching. Based on the recovery behavior of the PL fatigue through the low-temperature annealing, the origin of the visible luminescence in porous silicon is discussed.