PHOTOLUMINESCENCE KINETICS OF ETCHED POROUS SILICON UNDER CONTINUOUS-WAVE LASER EXCITATION

The time dependence of photoluminescence (PL) intensity for porous sil icon (PS) under cw laser excitation was investigated. The samples etch ed in HNO3 exhibit rapid PL buildup. To explain the observed changes i n the PL of PS under UV irradiation, we propose a model according to w hich the time dependence of PL intensity is dominated by the compositi on of surface emitting centers. Relying on this model, we calculate th e rate constants of relevant photochemical reactions and the kinetic c urves for adsorption of hydrogen and oxygen.