Stimulated Emissions in Aligned CdS Nanowires at Room Temperature

Aligned CdS nanowires (NWs) were obtained through a simple thermal evaporation process with highly active CdS nanoparticles as the evaporation source. These NWs show prominent optical waveguides behavior under a continuous-wave (CW) laser excitation. Excitation intensity-dependent photoluminescence (PL) measurements show that these NWs exhibited both broad and supernarrow stimulated emission (lasing) under intense pulse optical excitation at room temperature. Raman scattering and time-resolved PL measurements were used to investigate the optical properties. The results indicated that the stimulated emission in these NWs involves the electron−hole plasma (EHP) and Farby−Perot (F−P) optical resonant processes at room temperature.