Photo-stability of CsPbBr3 perovskite quantum dots for optoelectronic application

Abstract

Due to their superior photoluminescence (PL) quantum yield (QY) and tunable optical band gap, all-inorganic CsPbBr3 perovskite quantum dots (QDs) have attracted intensive attention for the application in solar cells, light emitting diodes (LED), photodetectors and laser devices. In this scenario, the stability of such materials becomes a critical factor to be revealed. We hereby investigated the long-term stability of as-synthesized CsPbBr3 QDs suspended in toluene at various environmental conditions. We found light illumination would induce drastic photo-degradation of CsPbBr3 QDs. The steady-state spectroscopy, transmission electron microscopy (TEM), and X-ray diffraction (XRD) verified that CsPbBr3 QDs tend to aggregate to form larger particles under continuous light soaking. In addition, decreasing PL QY of the QDs during light soaking indicates the formation of trap sites. Our work reveals that the main origin of instability in CsPbBr3 QDs and provides reference to engineer such QDs towards optimal device application.

CsPbBr3 QD/AlOx Inorganic Nanocomposites with Exceptional Stability in Water, Light, and Heat

“…Thelower density of the alumina matrix and decreased conformity of the alumina layer on the QD surface might explain this observation. [17,38] Instead, the nanocomposites showed minimal PL quenching after 8h of irradiation with no apparent energy shifts. Photosoaking experiments were conducted under simulated solar spectrum irradiation in air.F igure 3C shows the dramatic decay in PL intensity and energy red shift of the pristine QDs that result from ac ombination of chemical and photodegradation.…”

“…Photosoaking experiments were conducted under simulated solar spectrum irradiation in air.F igure 3C shows the dramatic decay in PL intensity and energy red shift of the pristine QDs that result from ac ombination of chemical and photodegradation. [17,38] Instead, the nanocomposites showed minimal PL quenching after 8h of irradiation with no apparent energy shifts. However,w hen the irradiation power density was increased from 10 mW cm À2 to 100 mW cm À2 ,a ni rreversible PL intensity quenching of more than 50 %w as observed after 8h, which stabilized afterwards ( Figure S17).…”

“…However,w hen the irradiation power density was increased from 10 mW cm À2 to 100 mW cm À2 ,a ni rreversible PL intensity quenching of more than 50 %w as observed after 8h, which stabilized afterwards ( Figure S17). [17,38] An alternative explanation for this quenching effect at higher irradiation densities is the photoinduced desorption of surface ligands and the subsequent formation of carrier trapping defects,a sp reviously reported for chalcogenide QD films. Quenching was still observed in additional UV-filtered and air-free photosoaking experiments ( Figure S19), which allows one to exclude the contribution of photochemical degradation of the ligands from the alumina band gap (> 3.4 eV) excitation and also of UV-induced coarsening.…”

High‐Performance All‐Inorganic Perovskite‐Quantum‐Dot‐Based Flexible Organic Phototransistor Memory with Architecture Design

“…Electron. [47][48][49] Moreover, the re-absorption process was accompanied by the repeated charge transfer process which was the same with illumination under 700 nm visible light. 2019, 5,1900864 where UV light was firstly converted into emitting radiation by perovskite QDs which were reabsorbed by PDVT-8 film subsequently.…”

Inorganic cesium lead halide CsPbX3 nanowires for long-term stable solar cells

“…However, hybrid perovskites are highly sensitive to moisture [10], ultraviolet (UV) light [11], and heat [12], which hinders their forward application [13,14]. Lead halides are the usual degradation product of the hybrid perovskites [10,15], deteriorating the performance of the solar cells, stemming from the wide bandgap and poor electrical conductivity [16,17].…”