High‐Quality Whispering‐Gallery‐Mode Lasing from Cesium Lead Halide Perovskite Nanoplatelets

Abstract

Semiconductor micro/nano‐cavities with high quality factor (Q) and small modal volume provide critical platforms for exploring strong light‐matter interactions and quantum optics, enabling further development of coherent and quantum photonic devices. Constrained by exciton binding energy and thermal fluctuation, only a handful of wide‐band semiconductors such as ZnO and GaN have stable excitons at room temperature. Metal halide perovskite with cubic lattice and well‐controlled exciton may provide solutions. In this work, high‐quality single‐crystalline cesium lead halide CsPbX3 (X = Cl, Br, I) whispering‐gallery‐mode (WGM) microcavities are synthesized by vapor‐phase van der Waals epitaxy method. The as‐grown perovskites show strong emission and stable exciton at room temperature over the whole visible spectra range. By varying the halide composition, multi‐color (400–700 nm).WGM excitonic lasing is achieved at room temperature with low threshold (~ 2.0 μJ cm−2) and high spectra coherence (~0.14–0.15 nm). The results advocate the promise of inorganic perovskites towards development of optoelectronic devices and strong light‐matter coupling in quantum optics.

Up-Conversion Perovskite Nanolaser with Single Mode and Low Threshold

“…39 This assumption can be confirmed by the simulated electric fields distributions shown in Figure 3c, where the emission are restricted by the total internal reflection at the interfaces between the NC edge and vacuum (white dashed square shows the shape of perovskite nanoplate), showing WGM oscillation behaviors. 24,39 Also, the calculated laser emission spectrum of the single mode is showed in Figure 3d, which is in a good agreement with our experimental result, and further prove our theoretical considerations. One thing should be mentioned is that due to the reason of sample preparation method, it is inevitable that some small particle will be attached on or next to the nanoplate we measured.…”

Probing molecule-like isolated octahedra via phase stabilization of zero-dimensional cesium lead halide nanocrystals

“…The overall superior PL QY of Mn 2+ -doped Cs 4 PbX 6 colloids (X = Br/Cl, Cl) is attributed to the spatially confined zero-dimensional structure, and presence of dopant at the isolated octahedra favoring enhanced dopant emission through the localized excitons and high exciton binding energy (Supplementary Figure 11b to 11e). The reported exciton binding energies of Cs 4 PbBr 6 and Cs 4 PbCl 6 are 353 3 and 153 eV 47 , respectively, compared to CsPbBr 3 (19 to 62 meV) and CsPbCl 3 (72 meV) 48–50 . These results suggest that the high luminescent Cs 4 PbX 6 nanocrystals doped with Mn 2+ could represent promising emitting materials for efficient solid-state lighting applications.…”

Fully‐Inorganic Trihalide Perovskite Nanocrystals: A New Research Frontier of Optoelectronic Materials

“…[21] Several research groups independently revealed the amplified spontaneous emission (ASE) from newly engineered CsPbX 3 (X = Cl, Br, I, and mixed Cl+Br and Br+I systems) colloidal NCs thin films. [59], 2.5 µJ cm −2 from ref. It was found that RT optical amplification can be obtained in the whole visible spectral region with low pump thresholds (e.g., the reported values for CsPbBr 3 NCs film: 2.2 µJ cm −2 from ref.…”

“…[42]). Apparently, the aforementioned superior optical www.advmat.de www.advancedsciencenews.com merits provide solid foundation for optoelectronic applications in light harvester, [43][44][45][46] LEDs, [33,34,[47][48][49][50][51][52][53][54][55][56] high-definition displays, [33,48] low-threshold lasers, [40,[57][58][59][60] and photodetectors. [33] In spite of the superiority to metal chalcogenide QDs, the main shortcoming of all-inorganic perovskite NCs is the degradation under service environment (see details in section 5).…”