HIGH TEMPERATURE STABILITY OF OPTICAL PROPERTIES OF InAs QUANTUM DOTS REALIZED BY CONTROLLING OF QUANTUM DOTS ELECTRONIC SPECTRUM

摘要

The optical properties of InAs/(Al)GaAs quantum dots (QDs) overgrowth by thin AlAs/InAlAs layers are studied as a function of temperature from 10 to 500 K. The QDs emit at 1.27μm at room temperature. It is shown that the QD energetic spectrum can be tuned by overgrowth of AlAs/InAlAs to provide high temperature stability of the QDs optical properties. Transport of carriers between neighboring QDs is absent, and the carrier distribution remains nonthermal up to room temperature. It is shown that suppression of the thermal escaping of the carriers from QDs is conditioned by high energy separation between ground and excited states, absence of wetting layer level, and increase of carrier localization energy in QDs in case of the Al0.3Ga0.7As matrix.