Whispering gallery mode lasing in lead halide perovskite crystals grown in microcapillary

Abstract

Microcapillaries enable us to simply prepare crystalline perovskites in a microcavity. A precursor solution of methyl ammonium lead bromide (CH3NH3PbBr3) is injected by capillary action into quartz microcapillaries with an inner diameter (ϕ) of 2–40 μm. After drying at 70 °C in the atmosphere, cylindrical crystals are precipitated to fill up the inner cavity of the microcapillary. Under optical pumping, whispering gallery mode lasing depending on ϕ is observed. With reducing ϕ, the mode number and the lasing threshold fluence are found to be decreased. This suggests that the stimulated emission can be enhanced by cavity quantum electrodynamics in CH3NH3PbBr3 crystals which are densely confined in the microcavity. Consequently, the microcapillary with ϕ = 2 μm realizes single-mode lasing at a threshold fluence of 4.7 μJ/cm2.

State of the Art and Prospects for Halide Perovskite Nanocrystals

“…coated a thin film of CsPbBr 3 NCs onto the inner wall of a capillary tube to realize high-performance WGM lasers with a quality factor (Q-factor) of ∼2000 (Figure c) . The occurrence of evenly spaced spikes and super-linear increase of the integrated PL intensity versus pump fluence (inset in Figure c, left) confirmed the development of lasing action, and the longitudinal optical modes could be well-assigned according to the WGM model. − Recently, by embedding a CsPbBr 3 –SiO 2 spheres into a microtubule, the frequency up-converted WGM lasing over 140 min with a low lasing threshold of 430 μJ cm –2 has been successfully achieved under two-photon excitation. Combining the effects of natural microring resonator of SiO 2 and high gain of CsPbBr 3 NCs provides a promising strategy to realize frequency up-converted lasing devices with low threshold …”

Amplified Spontaneous Emission and Lasing in Lead Halide Perovskites: State of the Art and Perspectives

“…Strain induced dynamic modulation of the lasing modes was also demonstrated and ascribed to piezoeletric polarization effects on the CsPbBr 3 gain region and refractive index. Another strategy to realize resonant cavity with controlled and reproducible size and shape, still preserving the easy realization, is given by the perovskite growth on dielectric resonators, like microspheres [62,63] or microcapillaries [64]. The first results with this approach were obtained by Sutherland et al [62] that developed a growth process allowing the conformal coating of a SiO 2 microsphere, with a diameter of 52 µm, with a MAPbI 3 film with excellent thickness uniformity (see Figure 10a).…”

Micro‐ and Nanostructured Lead Halide Perovskites: From Materials to Integrations and Devices

“…Taking advantage of the optical feedback provided by silica microcapillaries, WG mode lasing has also been demonstrated based on perovskite nanocrystals. [ 55–58 ]…”