Optoelectronics: Enhanced Stability and Tunable Photoluminescence in Perovskite CsPbX₃/ZnS Quantum Dot Heterostructure (Small 21/2017)

Abstract

A novel architecture made of a CsPbX3/ZnS quantum dot heterostructure is reported, by Xiaosheng Tang, Miao Zhou, and co‐workers in article number https://doi.org/10.1002/smll.201604085, by combining material synthesis, characterization, optical measurements and density functional theory based first‐principles calculations. This architecture presents high crystal quality, enhanced structural stability and tunable optoelectronic properties, providing an exciting playground for future exploration of novel and high‐performance optoelectronic devices.

Metal Halide Perovskite Nanocrystals: Synthesis, Post-Synthesis Modifications, and Their Optical Properties

“…This leads us to another challenge: that of creating stable heterostructures between halide perovskite NCs and inorganic compounds. Encouraging results have been reported on stable epitaxial interfaces between lead halide perovskites and Pb chalcogenides, , ZnS, and, recently, Cs 4 PbBr 6 . The final target would be, undoubtedly, the production of core/shell nanostructures in which MHP NCs will be completely covered by a shell of a robust inorganic material, such as metal chalcogenides, oxides, or fluorides.…”

“…In order to improve the stability of LHP NCs, different attempts to cover them with inorganic shell materials have also been reported. 244 By adding proper amounts of zinc stearate and 1-dodecanethiol at a high temperature (e.g., 120 °C) to presynthesized CsPbX 3 NCs, ZnS domains could be grown on their surface, boosting their photostability. 244 …”

“…242,243 In order to improve the stability of LHP NCs, different attempts to cover them with inorganic shell materials have also been reported. 244 By adding proper amounts of zinc stearate and 1-dodecanethiol at a high temperature (e.g., 120 °C) to presynthesized CsPbX 3 NCs, ZnS domains could be grown on their surface, boosting their photostability. 244 While 3D LHP NCs (e.g., CsPbBr 3 NCs) are extremely sensitive to water, treating Cs 4 PbBr 6 NCs dispersed in a nonpolar solvent with water can trigger a 0D → 3D transformation.…”

“…244 By adding proper amounts of zinc stearate and 1-dodecanethiol at a high temperature (e.g., 120 °C) to presynthesized CsPbX 3 NCs, ZnS domains could be grown on their surface, boosting their photostability. 244 While 3D LHP NCs (e.g., CsPbBr 3 NCs) are extremely sensitive to water, treating Cs 4 PbBr 6 NCs dispersed in a nonpolar solvent with water can trigger a 0D → 3D transformation. 245 This indirect method was then exploited in a new sol−gel approach for the surface modification of CsPbBr 3 NCs at a single particle level.…”

Lead Halide Perovskite Nanocrystals–Phospholipid Micelles and Their Biological Applications: Multiplex Cellular Imaging and in Vitro Tumor Targeting

“…There is one thing worth noting: comparing with the PL spectra of CsPbBr 3 NCs and CsPb­(Br/Cl) 3 NCs (Figure S3), the emission peak near 482 nm of CsPb­(Br/Cl) 3 @DOPC, C 9 B 1 @DOPC, and C 4 B 1 @DOPC shows a red shift relative to CsPb­(Br/Cl) 3 NCs, while the emission peak near 514 nm of C 9 B 1 @DOPC shows a blue shift relative to CsPbBr 3 NCs. These spectral shifts are caused by the instability of CsPb­(Br/Cl) 3 NCs in comparison with CsPbBr 3 NCs, in which Cl/Br ratio may change during the mixing and stirring process in ambient air . On the contrary, when CsPbBr 3 @DOPC and CsPb­(Br/Cl) 3 @DOPC were mixed together with different volume proportions, the emission peaks of the mixture remained unshifted; even the PL intensity ratio between CsPbBr 3 @DOPC and CsPb­(Br/Cl) 3 @DOPC maintains nearly the same as their volume ratio (Figure c).…”