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Colloidal semiconductor quantum dots(QDs)have potential applications in light-emitting diodes(LEDs)for the next generation flat panel display and solid-state lighting sources because of their size-and composition-tunable photoluminescence(PL)and high emission quantum efficiency.However,the efficiency is strongly temperature-dependent.For most applications in high-brightness lighting devices,the working temperature is in the range of 80-200 ℃.The significant high temperature(300-500 K)PL quenching was observed in undoped quantum dots with high quality,which was explained in terms of irreversible quenching that originates from thermally induced permanent structural changes and reversible quenching that comes from either thermally activated escape of carriers to existing(surface)trap states and/or the thermally activated creation of trap states [1].