Lasing from Zero-Dimensional Perovskite and Optical Imaging Applications

Abstract

Owing to quantum confinement of optical and electrical transitions within isolated [PbBr 6 ] 4− octahedral units, zero-dimensional perovskite Cs 4 PbBr 6 exhibits appealing molecular-like quantum optoelectronic behavior. Although much effort has been made thus far, the origin of the visible photoluminescence observed in Cs 4 PbBr 6 still remains unclear. In addition, its stimulated emission and potential applications are rarely explored. Here, phase-pure Cs 4 PbBr 6 microcrystals with well-defined morphology are developed via an antisolvent approach and exhibit intense photoluminescence centered at ∼518 nm with a photoluminescence quantum yield of ∼30% and a rather large binding energy of ∼267 meV. Optical spectroscopic and systematic structural analyses consistently suggest that the obtained product is phase-pure Cs 4 PbBr 6 . In particular, optical spectroscopic analyses reveal for the first time the agreement between the photoluminescence excitation spectrum and localized optical absorption of Pb 2+ in isolated [PbBr 6 ] 4− octahedra. Thus, the green photoluminescence is viewed intrinsic to Cs 4 PbBr 6 . Single-and multimode lasing resonances are demonstrated in individual Cs 4 PbBr 6 microcrystals upon optical pumping. Potential application of the Cs 4 PbBr 6 laser is demonstrated to achieve speckle-free imaging of micrometer-scaled objects when a single Cs 4 PbBr 6 microcrystal laser is utilized as the illumination source. The results suggest that zero-dimensional perovskites support lasing resonance and hold important potential applications in optoelectronics.

Low‐Dimensional‐Networked Cesium Lead Halide Perovskites: Properties, Fabrication, and Applications

“…In the synthesis of single crystals, antisolvent vapor-assisted crystallization is a well-established method. To obtain Cs 4 PbBr 6 crystals, CsBr/PbBr 2 (typically 1:1 [39] or 4:1 [51,53,123] molar ratio) in DMSO were injected into a vial and then stored in a closed glass container under an antisolvent atmosphere (Figure 8a), which was one of either diethyl-ether, dichloromethane or acetone. [39,51,53,81,123] The high vapor pressure of the antisolvent enabled its rapid diffusion into the vial, leading to the formation of crystals.…”

“…In terms of Cs 4 PbBr 6 with green emission, it too could be employed into the fabrication of high-quality lasers as well. [54,123] The single-mode laser demonstrated low lasing thresholds and high-quality factors under both one-and twophoton excitation. Strikingly, the integrated PL intensity under a continuous pulsed laser of 800 nm lasted for more than 2 h. These lasers have shown great potential in various applications.…”

“…To obtain Cs 4 PbBr 6 crystals, CsBr/PbBr 2 (typically 1:1 [ 39 ] or 4:1 [ 51,53,123 ] molar ratio) in DMSO were injected into a vial and then stored in a closed glass container under an antisolvent atmosphere ( Figure a), which was one of either diethyl‐ether, dichloromethane or acetone. [ 39,51,53,81,123 ] The high vapor pressure of the antisolvent enabled its rapid diffusion into the vial, leading to the formation of crystals. After 48–72 h, the as‐formed Cs 4 PbBr 6 single crystals were collected and dried under vacuum.…”

0D Perovskites: Unique Properties, Synthesis, and Their Applications

“…reported 0D perovskite lasers based on pure phase Cs 4 PbBr 6 microcrystals, which exhibits single‐ and multimode lasing resonance upon optical pumping with picosecond laser pulses. [ 139 ] The PL spectra of Cs 4 PbBr 6 microcrystal was narrowed with the increase of pump fluence, as shown in Figure 12e , indicating the occurrence of lasing resonance. The number of lasing modes can be tuned by adjusting the particle size.…”

“…f) Schematic of the optical setup for speckle-free imaging. e,f) Reproduced with permission [139]. Copyright 2019, American Chemical Society.…”