Vapor Phase Growth of Centimeter‐Sized Band Gap Engineered Cesium Lead Halide Perovskite Single‐Crystal Thin Films with Color‐tunable Stimulated Emission

Abstract

Single crystal metal halide perovskites thin films are considered to be a promising optical, optoelectronic materials with extraordinary performance due to their low defect densities. However, it is still difficult to achieve large-scale perovskite single-crystal thin films (SCTFs) with tunable bandgap by vaporphase deposition method. Herein, the synthesis of CsPbCl 3(1-x) Br 3x SCTFs with centimeter size (1 cm × 1 cm) via vapor-phase deposition is reported. The Br composition of CsPbCl 3(1-x) Br 3x SCTFs can be gradually tuned from x = 0 to x = 1, leading the corresponding bandgap to change from 2.29 to 2.91 eV. Additionally, an low-threshold (≈23.9 µJ cm −2 ) amplified spontaneous emission is achieved based on CsPbCl 3(1-x) Br 3x SCTFs at room temperature, and the wavelength is tuned from 432 to 547 nm by varying the Cl/Br ratio. Importantly, the high-quality CsPbCl 3(1-x) Br 3x SCTFs are ideal optical gain medium with high gain up to 1369.8 ± 101.2 cm −1 . This study not only provides a versatile method to fabricate high quality CsPbCl 3(1-x) Br 3x SCTFs with different Cl/Br ratio, but also paves the way for further research of colortunable perovskite lasing.

Optoelectronic Devices of Large-Scale Transferred All-Inorganic Lead Halide Perovskite Thin Films

“…Perovskites can act as excellent gain media because of their high oscillator strength and absorption coefficient. − Furthermore, the large difference in the refractive index between the perovskite and air enables the interface between them to be regarded as a high-reflectivity mirror. − As shown in Figure S6, the edges of the perovskite films with vertical sides can act as reflectivity mirrors. Figure b shows that the resonator of perovskite film is the in-plane Fabry–Pérot (F-P) cavity, which consists of a pair of interfaces between CsPbBr 3 and the air boundary.…”

All-inorganic lead halide perovskite nanocrystals applied in advanced display devices

“…In the structural framework of ABX 3 , X À anions are present in large amounts among three chemical elements, and decide the photonic band gap of the luminous material. 76 The reaction of ion-exchange commonly occurs in material preparation. [77][78][79] Cation-exchange is facile and common, while anion-exchange reactions are uncommon in AILHP QDs.…”

Modal gain enhancement of perovskite nanosheets by a patterned waveguide via spectral-length gain analysis

“…Metal halide perovskites (MHPs) show many outstanding features such as low-cost solution processability, precise bandgap tunability over the entire visible spectral range, and high quantum yield [1,2], these advantages can be used in a broad range of applications such as solar cells [3,4], light-emitting diodes [5,6], laser diodes [7][8][9][10][11][12][13], and photodetectors [14,15]. Although organicinorganic perovskites were studied a great deal, all inorganic perovskites were found to be superior in terms of thermal stability and moisture sensitivity [16,17].…”

“…On the other hand, all inorganic perovskite CsPbBr 3 film is known to have a large number of defects in its polycrytalline morphology. Recently, this obstacle was resolved by a large scale single-crystal film of CsPbBr 3 , where a low threshold (∼ 24 µJcm −2 ) was observed, and the gain was measured to be up to 1369 ± 101 cm −1 with an excitation fluence of ∼ 720 µJcm −2 [10].…”