title: Temperature-dependent excitonic photoluminescence excited by two-photon absorption in perovskite CsPbBr3quantum dots.
abstract: Recently, lead halide perovskite quantum dots have been reported with potential for photovoltaic and optoelectronic applications due to their excellent luminescent properties. Herein excitonic photoluminescence (PL) excited by two-photon absorption in perovskite CsPbBr3quantum dots (QDs) has been studied at a broad temperature range, from 80 to 380 K. Two-photon absorption has been investigated and the absorption coefficient is up to 0.085 cm/GW at room temperature. Moreover, the PL spectrum excited by two-photon absorption shows a linear blue-shift (0.32 meV/K) below the temperature of 220 K. However, for higher temperatures, the PL peak approaches a roughly constant value and shows temperature-independent chromaticity up to 380 K. This behavior is distinct from the general red-shift for semiconductors and can be attributed to the result of thermal expansion, electron-phonon interaction and structural phase transition around 360 K. The strong nonlinear absorption and temperature-independent chromaticity of CsPbBr3QDs observed in temperature range from 220 to 380 K will offer new opportunities in nonlinear photonics, light-harvesting, and light-emitting devices.
authors: Ke
authors: K
authors: Wei
authors: Zhongjie
authors: Z
authors: Xu
authors: Runze
authors: R
authors: Chen
authors: Xin
authors: X
authors: Zheng
authors: Xiangai
authors: X
authors: Cheng
authors: Tian
authors: T
authors: Jiang