High Efficiency Up‐Conversion Random Lasing from Formamidinium Lead Bromide/Amino‐Mediated Silica Spheres Composites

Abstract

Formamidinium (HC(NH2)+; FA) lead halide perovskites have emerged as potential candidates for solar cells, light‐emitting diodes, and lasing applications. However, the severely poor photostability of this material under UV irradiation seriously restricts the application on optoelectronic devices. In this paper, formamidinium lead halide (FAPbX3) quantum dots (QDs) adhered uniformly on the surface of amino‐mediated silica (A‐SiO2) spheres are successfully synthesized using a facile ligand‐assisted reprecipitation (LARP) method. Amazingly, the FAPbBr3/A‐SiO2 composites demonstrate excellent photostability after continuous illumination under UV lamps due to the effective suppression of the interactions and mutual contact between FAPbBr3 particles. In addition, the up‐conversion random lasing with a high quality (Q) factor of 1307 and low threshold of 413.7 µJ cm‐2 is successfully achieved from the FAPbBr3/A‐SiO2 composites at room‐temperature, which originates from the multiple random scattering of light and photon recycling provided by the silica spheres and the high gain characteristic of FAPbBr3 QDs. Moreover, different from regular lasers, random lasing does not rely on a laser cavity, which is promising in angle‐unlimited optical performance and easy/low‐cost fabrication. This work will open the window of high‐performance random lasers for digital light projector, high speed imaging, and speckle‐free full‐field imaging application.

Advances in metal halide perovskite lasers: synthetic strategies, morphology control, and lasing emission

“…9(d)-9(f)]. 131 Similarly, Yang et al 136 realized upconversion random lasing from FAPbBr 3 ∕A-SiO 2 composites with a threshold of ∼413.7 μJ∕cm 2 . Liu et al 137 obtained WGM and random lasing with a threshold of ∼430 μJ∕cm 2 under 800 nm excitation by embedding CsPbBr 3 QDs into a single silica sphere.…”

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

“…Xing et al first found amplified spontaneous emission in perovskite thin films in 2014; since then, the laser behaviors of perovskite have been studied all over the world. , Lasing had been observed from perovskite cavities with different resonator modes, including whispering gallery mode (WGM) cavity, Fabry–Pérot cavity, , photonic crystal, , random cavity, , plasmon cavity, , distributed feedback resonator, , and so on . Among all these cavities, WGM cavities were found to exhibit the strongest confinement effect due to their total internal reflection around the cavities, which results in the excellent optical feedback .…”

Threshold Size Effects in the Patterned Crystallization of Hybrid Halide Perovskites for Random Lasing

“…Random lasing has been achieved in such materials in forms of thin films and powders. [ 26–30 ] A sandwiched structure has been produced by spin coating the perovskite precursor between two distributed Bragg reflectors, thus, surface emitting random laser was achieved with a divergence angle of 3°−5°. [ 30 ] Random lasing effect has been investigated in high‐quality CH 3 NH 3 PbBr 3 perovskite thin films on different substrates, [ 30 ] where patterned sapphire substrates (PSSs) facilitated a lasing threshold more than one order lower than the fluorine‐doped tin oxide (FTO) ones, revealing important photophysical mechanisms.…”