Continuous wave pumped single-mode nanolasers in inorganic perovskites with robust stability and high quantum yield

113

Lead halide perovskites are considered as very promising photovoltaic materials due to their tunable direct bandgaps, large absorption coefficients, long carrier diffusion lengths, and ultralow trap state densities, etc. With these unique properties, the lead halide perovskites have also demonstrated great potential for use as semiconductor gain materials. In this review, a snapshot on the recent advances of lead halide perovskite micro‐ and nanolasers is given. The dependence of lasing performance on the perovskite dimensionality, crystal size, and operation temperature is systematically discussed. Furthermore, the development of continuous wave (cw) pumped perovskite lasers and lead‐free perovskite lasers is also summarized. In the final section, the challenges and future prospects of metal halide perovskite lasers are provided. These pieces of knowledge would help advancing the development of perovskite on‐chip coherent light sources.

Section: Different Dimensional Metal Halide Perovskites For Lasingmentioning

confidence: 91%

Section: Continuous‐wave Pumped Perovskite Lasingmentioning

confidence: 99%

Recent Progress in Metal Halide Perovskite Micro‐ and Nanolasers

Wei

Liang

et al. 2019

113

“…However, most research has been focused on encapsulating PQDs with polymers, which is unfavorable for higher‐temperature environment applications . Second, the ability to obtain a stable, single layer of PQDs microspheres which can be used to achieve secondary nanostructures on micron block materials is highly desired . Third, the current most popular hydrolysis encapsulation method requires toluene as a solvent, along with relatively high humidity, which is fatal to iodine‐based perovskites .…”

Section: Introductionmentioning

confidence: 99%

CsPbBr₃‐Quantum‐Dots/Polystyrene@Silica Hybrid Microsphere Structures with Significantly Improved Stability for White LEDs

Yang

Gao

Qiu

et al. 2019

Cesium‐lead‐halide perovskite quantum dots (PQDs), which have superior optical and electronic properties, are regarded as excellent materials for various optoelectronic devices. However, their unstable nature greatly hinders their practical application. Herein, a simple hydrolysis encapsulation method is developed to embed PQDs into mesoporous polystyrene microspheres (MPMs) followed by a silica shell covering process, which generates luminescent PQDs/MPMs@SiO2 hybrid microspheres with significantly enhanced stability. The obtained CsPbBr3‐PQDs/MPMs@SiO2 hybrid microspheres show a high photoluminescence quantum yield of 84%. More importantly, the MPMs@silica protective shells effectively cut off direct contact between outer erosive species and the inner embedded PQDs and modify the hybrid microspheres with ultralong alkyl chains for improved resistance to solvents and heat. Hence, these CsPbBr3‐PQDs/MPMs@SiO2 hybrid microspheres exhibit good chemical/physical stabilities, even when exposed to harsh environments, such as deionized water, isopropanol, acid/alkali solution, anion‐exchange reactions, and heating. Particularly, the water stability, which produced the remaining ≈48% proportion of the initial fluorescence intensity after a quite long aqueous storage period of 30 d, is the best reported among the stability‐related studies of PQDs. Meanwhile, white light‐emitting diodes (LEDs) are achieved by mixing green CsPbBr3‐PQDs/MPMs@SiO2 microspheres with red commercial phosphors on a blue chip. High power efficiency of 81 lm W−1 and good electroluminescence stability are obtained.

“…In particular, single‐crystalline micro‐/nanostructures with low defect densities are expected as an ideal platform for achieving robust CW lasing emission. [ 17,18 ] However, in previous reports, these single‐crystalline structures only served as free‐standing micro‐/nanolasers, which exhibited relatively weak optical confinement. Vertical cavity surface emitting lasers (VCSELs) by using high‐reflectance distributed Bragg reflectors (DBRs) is an effective configuration for providing a strong confined optical field to realize low‐threshold CW lasers.…”

Section: Figurementioning

confidence: 99%

Continuous‐Wave Vertical Cavity Surface‐Emitting Lasers based on Single Crystalline Lead Halide Perovskites

Zou

Chen

et al. 2021

Lead halide perovskites are intriguing semiconductors for lasers due to high quantum yield, tunable bandgaps, and facile solution‐process ability. However, limited by the weak optical confinement, continuous‐wave (CW) pumped lasing, as one prerequisite for the electrically pumped lasing, is still challenging in bare lead halide perovskites without high‐quality factor (Q) artificial optical cavity. Herein, the lasing emission in methylammonium lead tribromide (MAPbBr3) incorporated with a vertical microcavity under continuous pumping at 80 K is reported. The single‐crystalline MAPbBr3 perovskite nanoplates are fabricated by the two‐step solution method. The MAPbBr3‐based vertical cavity surface‐emitting laser (VCSEL) presents a low threshold of 55.2 W cm−2 and a high Q‐factor of 1140 at low temperature. The low threshold lasing emission can be attributed to strong optical confinement in the high‐Q cavity and great photoluminescence enhancement at 80 K, which is induced by a transition from tetragonal to orthorhombic phase, demonstrated by in situ temperature Raman spectroscopy. These findings envisage the prospective applications of single‐crystalline metal halide perovskites in practicable laser devices.