Temperature-dependent photoluminescence of inorganic perovskite nanocrystal films

Abstract

The photoluminescence stability of all-inorganic perovskite nanocrystals (CsPbBr3) with different size is studied.

Solution‐Grown CsPbBr3/Cs4PbBr6 Perovskite Nanocomposites: Toward Temperature‐Insensitive Optical Gain

“…To figure out the distinct temperature dependence of the SE spectral position, the spontaneous emission from colloidal CsPbBr 3 and CdSe/CdS QDs at varied temperatures was recorded (Figure S5, Supporting Information). We can see that the PL peak wavelength for CdSe/CdS QDs continuously redshifts (≈0.12 nm per °C) as the temperature increases, while CsPbBr 3 QDs exhibit a nearly temperature independent PL position, which is consistent with previous reports . Since the seed photons for SE are provided by the spontaneous emission (exciton and/or biexciton emission), it is not surprising that the SE peak position follows the same trend as the corresponding spontaneous emission .…”

“…Therefore, the band gap of CsPbBr 3 will increase as a result of the lattice dilution . Consequently, the compensation between the lattice dilution and the electron–phonon interaction in CsPbBr 3 QDs gives rise to the nearly temperature independent emission and SE spectrum ranging from 20 to 100 °C . As a result of essentially the same antibonding type of VBM for varied halide compositions (Cl, Br, or I), similar temperature dependent VBM can be anticipated.…”

“…They also exhibit strong nonlinear absorption and thus two‐photon pumped lasing has been achieved with low threshold . Notably, in stark contrast to the traditional QDs, the CsPbBr 3 QDs show nearly temperature‐independent PL peak position from ≈20 to ≈100 °C due to the unique electronic structure as will be elaborated later, promising to sustain the temperature‐insensitive gain chromaticity . Unfortunately, these colloidal CsPbX 3 QDs were found to show relatively poor thermal stability because of the damage of ligands and the ensuing particle aggregation or fusion at elevated temperatures, reflected by the rapid PL quenching and ripening of the nanocrystals .…”

“…Notably, in stark contrast to the traditional QDs, the CsPbBr 3 QDs show nearly temperature‐independent PL peak position from ≈20 to ≈100 °C due to the unique electronic structure as will be elaborated later, promising to sustain the temperature‐insensitive gain chromaticity . Unfortunately, these colloidal CsPbX 3 QDs were found to show relatively poor thermal stability because of the damage of ligands and the ensuing particle aggregation or fusion at elevated temperatures, reflected by the rapid PL quenching and ripening of the nanocrystals . It is further noted that the overwhelmingly employed core–shell structure in metal–chalcogenide QDs for stability enhancement is not applicable for halide perovskite nanocrystals so far due to the spontaneous anion‐exchange reactions …”

“…[34][35][36] Unfortunately, these colloidal CsPbX 3 QDs were found to show relatively poor thermal stability because of the damage of ligands and the ensuing particle aggregation or fusion at elevated temperatures, reflected by the rapid PL quenching and ripening of the nanocrystals. [34][35][36][37] It is further noted that the overwhelmingly employed core-shell structure in metal-chalcogenide QDs for stability enhancement is not applicable for halide perovskite nanocrystals so far due to the spontaneous anion-exchange reactions. [38,39] Herein, we addressed the above issues by fabricating a novel lasing material composed of ligands-free CsPbBr 3 nanocrystals embedded in a wider band gap Cs 4 PbBr 6 matrix based on low-temperature solution-phase synthesis.…”