Fabrication and red-color lasing of individual highly uniform single-crystal CdSe nanobelts

Highly uniform single-crystal CdSe nanobelts were prepared via a simple thermal evaporation route. Photoluminescence (PL) from a single belt indicates that the obtained nanostructures can produce stable and ultrafine red-color lasing under pulsed light excitation. The corresponding PL decay profiles show that the PL lifetime under high excitation is sharply shortened compared to that at low excitation power, which further supports that the PL in the nanobelt cavities can realize resonance and give stimulated emission. Comparative experiments with tapered belts show that the high PL emissions are mainly attributed to the uniform configuration of these nanostructures which can serve as a very effective waveguide cavity to realize high optical gain under high excitation. This kind of CdSe nanostructures may find potential applications in redlight nanolasers.