退火对InP / ZnS量子点薄膜光学性质的影响

he enhancement of optical properties via thermal annealing on InP/ZnS core/shell quantum dots (QDs) film was investigated in this work. The increase of emission intensities of the QDs films was observed after thermal annealing at 180 ℃ for 5 minutes. Through temperature dependence photoluminescence (TDPL) and power dependence photoluminescence (PL) measurement, the peak located at the low-energy shoulder was confirmed to be localized states emission and the high energy one comes from free-carrier emission. Moreover, from the TDPL spectra of the sample anneal at 180 ℃ for 5 minutes, the full width at half maximum (FWHM) of localization states emission was nearly the same before 250 K, and then decreased with increasing temperature. However, the FWHM was decreased significantly with temperature increased in the untreated sample. We conclude that the escape of localization states with increasing temperature contributes to this anomaly phenomenon. Our studies have significance on the application of QDs in electroluminescence or down-conversion light-emitting applications.