Temperature-dependent excitonic photoluminescence Excited by Two-Photon Absorption in Perovskite CsPbBr3 Quantum Dots

TL;DR

This study investigates the temperature-dependent excitonic photoluminescence excited by two-photon absorption in CsPbBr3 quantum dots, revealing unique blue-shift behavior and stable chromaticity across a broad temperature range, with implications for photonic applications.

Contribution

It provides the first detailed analysis of two-photon excited photoluminescence in CsPbBr3 quantum dots over a wide temperature range, highlighting nonlinear absorption and temperature-independent emission properties.

Findings

Two-photon absorption coefficient up to 0.085 cm/GW at room temperature.

Linear blue-shift of 0.25 meV/K below 220K, steady above.

Stable chromaticity from 220K to 380K, unaffected by temperature.

Abstract

Recently lead halide nanocrystals (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 CsPbBr3 quantum dots (QDs) have been studied across a broad temperature range from 80K to 380K. Two-photon absorption has been investigated with absorption coefficient up to 0.085 cm/GW at room temperature. Moreover, the photoluminescence excited by two-photon absorption shows a linear blue-shift (0.25meV/K) below temperature of ~220K and turned steady with fluctuation below 1nm (4.4meV) for higher temperature up to 380K. These phenomena are distinctly different from general red-shift of semiconductor and can be explained by the competition between lattice expansion and electron-phonon couplling.Our results reveal the strong nonlinear absorption and temperature-independent chromaticity in a large temperature range from 220K to 380K in the CsPbX3 QDs, which will offer new opportunities in nonlinear photonics, light-harvesting and light-emitting devices.