Room-Temperature Broad-Wavelength-Tunable Single-Mode Lasing from Alloyed CdSSe Nanotripods.

Wavelength-tunable semiconductor nanolasers have attracted tremendous attention for their tunable emissions and robust stability, bringing possibilities for various applications, including nanophotonic circuits, solid-state white-light sources, wavelength-converted devices, and on-chip optical communications. Here, we report on the demonstration of broadband-tunable, single-mode nanolasers based on high-quality alloyed single crystalline CdSSe ( = 0-1) nanotripods with well-formed facets fabricated using a conventional CVD approach. Microstructural characterization and optical investigations reveal that these structures are crystalline with composition-tunable CdSSe alloys. Microphotoluminescence spectra and mapping of these nanotripods exhibit emissions with continuous wavelengths from 509 to 712 nm, further demonstrating that the CdSSe alloys have tunable bandgaps due to the composition gradient. Additionally, under a pulse laser illumination, room-temperature single-mode lasing is clearly observed from these nanotripods cavities, which shows almost identical emission lines with a high-quality factor of ∼1231. More importantly, wavelength continuously tunable nanolasers from 520 to 738 nm are successfully constructed using these bandgap gradient nanotripods. The capability to fabricate high-quality tunable nanolasers represents a significant step toward high-integration optical circuits and photonics communications.