Whispering Gallery Mode Lasing from Perovskite Polygonal Microcavities via Femtosecond Laser Direct Writing

Abstract

Organic–inorganic halide perovskites have excellent intrinsic properties, such as long carrier lifetime, high photoluminescence quantum yield, and high gain, in whispering gallery mode (WGM) cavities by facile vapor self-assembly or solution process, which make them competitive for high-performance microlasers. However, the performance of perovskite-based microlasers is severely limited by the fabrication of microcavities, which results in poor reproducibility and uncontrolled morphology. Herein, we explore a reproducible method which combined thermal co-evaporation with femtosecond (fs) laser direct writing for formamidinium lead iodide (FAPbI3) perovskite polygon-shaped WGM microcavities. The microlasers pumped with the fs laser had a low threshold of 4.0–12.3 μJ/cm2 and narrow full width at half-maximum of 0.62–1.05 nm. Moreover, size- and shape-dependent WGM lasing performances are also investigated systematically. The results prove that FAPbI3 polygonal microcavities can serve as promising WGM lasers and have great potential for practical optoelectronic applications.

Directional Lasing from Nanopatterned Halide Perovskite Nanowire

“…Such processing conditions avoided the uneven coupling of the incident laser radiation in the CsPbBr 3 NW, which could result in preferential ablation near its corners, as illustrated by corresponding full-wave calculations (see Figure c). The fabrication method used demonstrated an accuracy that was high enough to imprint a subwavelength grating with a period Λ down to 200 nm, thus outperforming the previously reported approach based on scanning laser ablation. − A remarkable reproducibility of the fabrication approach used is revealed in Figure d where a 30 μm long CsPbBr 3 NW patterned with a 260 nm period nanograting on its top face is shown.…”

Highly Stable Lasing from Solution‐Epitaxially Grown Formamidinium‐Lead‐Bromide Micro‐Resonators

“…This number of laser pulses is about 1-3 orders of magnitude more than what is reported for different metal-halide perovskite microcavities kept in the air (Figure 5b). [17,19,27,[37][38][39][40] As a matter of fact, this value is even comparable or even higher than what was obtained for organic-inorganic hybrid metalhalide-perovskite lasers kept under nitrogen atmosphere. [12,41,42] To this day, only in a single report a higher value was derived for a device kept under nitrogen, which was obtained for an all-inorganic perovskite laser structure (Figure 5b and Table S2, Supporting Information).…”

Transient Lasing Behaviors in MAPbBr3 Perovskite Microcavities

“…In such a square resonator, the mode spacing δλ can be written as δλ = λ 2 /2√2 Ln g . From the relation in Figure d, the group refractive index n g in MAPbBr 3 single crystals is 4.8, comparable to that in inorganic perovskites. , The lasing thresholds decrease in large microplates with better photon confinement and lower optical loss . The quality factor decreases from 913 in the 6.3 μm microplate to 54 in the 27.2 μm microplate as shown in Figure S10.…”

“…9,29 The lasing thresholds decrease in large microplates with better photon confinement and lower optical loss. 30 The quality factor decreases from 913 in the 6.3 μm microplate to 54 in the 27.2 μm microplate as shown in Figure S10.…”