Water-resistant perovskite nanodots enable robust two-photon lasing in aqueous environment

Abstract

Owing to their large absorption cross-sections and high photoluminescence quantum yields, lead halide perovskite quantum dots (PQDs) are regarded as a promising candidate for various optoelectronics applications. However, easy degradation of PQDs in water and in a humid environment is a critical hindrance for applications. Here we develop a Pb-S bonding approach to synthesize water-resistant perovskite@silica nanodots keeping their emission in water for over six weeks. A two-photon whispering-gallery mode laser device made of these ultra-stable nanodots retain 80% of its initial emission quantum yield when immersed in water for 13 h, and a two-photon random laser based on the perovskite@silica nanodots powder could still operate after the nanodots were dispersed in water for up to 15 days. Our synthetic approach opens up an entirely new avenue for utilizing PQDs in aqueous environment, which will significantly broaden their applications not only in optoelectronics but also in bioimaging and biosensing.

Interface Chemical Modification between All-Inorganic Perovskite Nanocrystals and Porous Silica Microspheres for Composite Materials with Improved Emission

“…The treatment of the MSs with TEOS molecules followed by the pNCs embedding results in the improved pNCs penetration rate and optical parameters, such as an increase of the average PL lifetime. As was previously shown the use of silica precursors resulted in increased stability of optical responses from 12 h in the air [ 16 ] to up to 15 days in water [ 30 ] due to efficient passivation and protection of pNC from the environment. Thus, the developed in this work approach to change the chemical composition of the interface of pNC-based composites with TEOS molecules has proved to expand a toolkit in fabrication procedures of composites with improved performance for future photonics.…”

Amplified Spontaneous Emission and Random Lasing in MAPbBr3 Halide Perovskite Single Crystals

“…At the moment, most of the works are devoted to the study of amplified spontaneous emission (ASE) and lasing with pulsed optical pumping. The resonators used for lasing can be divided into three groups: random resonators, supporting random lasing (RL); [ 2–6 ] optical resonators based on the refractive index contrast between the synthesized perovskite material and air, such as micro‐ and nanocubes, [ 7–9 ] rods, [ 10,11 ] wires, [ 12–17 ] platelets, [ 18–20 ] micropyramids, [ 21 ] and microspheres; [ 22–24 ] and external resonators based on distributed Bragg reflectors, [ 25–28 ] capillary‐like microcavities, [ 29 ] photonic crystals, [ 30,31 ] gratings for distributed feedback lasers, [ 32–38 ] and nanolithographically fabricated microdisks. [ 39–41 ] The laser generation manifests itself in different ways.…”

Review of biosensing with whispering-gallery mode lasers

“…Currently, the main problems with perovskites in WGM microlasers and sensors are their degradation in aqueous media and low photostability 108 . Some attempts to alleviate the water instability of perovskites, which mainly affects the structural and emission performance, include encapsulation in a SiO 2 shell, with the resulting composite assembled into a tubular whispering-gallery microcavity 114 .…”