Photoluminescence beyond 1.5?m from InAs quantum dots
Photoluminescence measurements were carried out to investigate the origin of long wavelength emissions (?1.6?m at room temperature) observed from wafers with InAs quantum dots capped with GaAsSb layers. For wafers with high Sb content (22% and 26%) photoluminescence peak energies were found to be linearly proportional to third root of optical excitation power, a characteristic of emission due to a type-II band alignment. This work therefore presents unambiguous evidence that the long wavelength emission of the wafers comes from type-II band alignment between the InAs quantum dots and the GaAsSb capping layers.
photoluminescence quantum dots type-ii