Temperature-dependent photoluminescence of cesium lead halide perovskite (CsPbX₃, X = Br, Cl, I) quantum dots

Abstract

Inorganic halide perovskites (CsPbX3, X = Br, Cl, I) have recently been recognized owing to having good luminescent properties. In this work, the emission peak of these perovskites has been tuned in the region of 451–636 nm by varying the halide ion composition. Temperature-dependent photoluminescence (PL) spectroscopy was used to verify the thermal quenching of PL , blue shifting of band gaps and linewidth of broadening for the CsPbX3 (X = Br, Cl, I) QD films. On the basis of fitting data, the activation energy (ΔE) and Huang–Rhys factor (S) of the CsPbX3 (X = Br, Cl, I) QD films was obtained. On moving from X = I to Br to Cl, the decrease in ΔE indicates that the excited electrons easily returned to the groundstate without the emission of radiation, ΔE decreases as S increases, the increase in the Huang–Rhys factor is indicative of enhanced electron–phonon coupling.