Exciton photoluminescence of CsPbBr3@SiO2 quantum dots and its application as a phosphor material in light-emitting devices

In this report, we mainly investigate the optical property differences between CsPbBr₃@SiO₂ quantum dots (QDs) and CsPbBr₃ QDs. The photoluminescence demonstrates that CsPbBr₃@SiO₂ QDs and CsPbBr₃ QDs have similar exciton binding energy. Both CsPbBr₃ and CsPbBr₃@SiO₂ QDs present optical bandgaps and photoluminescence (PL) linewidth broadening as the temperature increases from 10 K to room temperature, which is attributed to the thermal expansion and electron-phonon coupling. The fitting results show that CsPbBr₃ and CsPbBr₃@SiO₂ QDs have the similar bandgap thermal expansion coefficient, but the CsPbBr₃@SiO₂ QDs have weaker electron-phonon interaction. Temperature-dependent timeresolved photoluminescence (TRPL) demonstrates that the PL lifetime increases with the temperature and CsPbBr₃@SiO₂ QDs have longer PL lifetime than CsPbBr₃ QDs after 110 K. In addition, the CsPbBr₃@SiO₂ QDs integrated on the blue light-emitting diode chip as green phosphor material show better thermal stability in ambient air.