Photoluminescence investigation of InAs quantum dots incorporating DWELL structures on patterned and planar GaAs (100) substrate

摘要

InAs quantum dots embedded in InGaAs quantum well (DWELL) structures grown by metal-organic chemical-vapor deposition on nano-patterned GaAs pyramids and planar GaAs (001) substrate are comparatively investigated. Photoluminescence (PL), PL excitation, and time-resolved PL measurements demonstrate that the DWELL grown on the GaAs pyramids has a broad QW PL band (FWHM ～90 meV) and a better QD emission efficiency than the DWELL structure grown on the planar GaAs (001) substrate. These properties are attributed to the InGaAs QW with distributed thickness profile on the faceted GaAs pyramid, which introduces tapered energy band structure and assists the carrier capture into the QDs. This research provides useful data for further improving the performance of DWELL structures for device applications.