Effect of temperature and pumping power on the photoluminescence properties of type-II CdTe/CdSe core-shell QDs

CdTe/CdSe core-shell QDs type II was prepared by two steps synthetic process and embedded in polymer host. Emission in the NIR region was recorded. The effect of Ar laser excitation at different powers on the optical properties of the prepared QDs is studied at different temperatures (300-10 K). Amplified spontaneous emission is observed at room temperature and at 10 K. Also, lifetime measurement of prepared QDs was documented using N2-laser.

► CdTe/CdSe core-shell NCs have very large stock shift which lead to appearance of the emission of such system near IR-region. ► The tunability of band gap from visible to IR region depend upon the thickness of shell and the size of core of prepared samples. ► Also, some optical properties of CdTe/CdSe core-shell QDs depending upon the different pumping power (1-200 mW) of 488 nm Ar-laser and depending also on the effect of different temperatures (100-10 K) were studied. Lifetime measurement of prepared QDs was documented by using N2-laser. ► CdTe/CdSe core-shell NCs are good lasing materials with lifetime exceed 7 ns because of very large stock shift which prevents the reabsorption and increase quantum yield.