Air-Stable Surface-Passivated Perovskite Quantum Dots for Ultra-Robust, Single- and Two-Photon-Induced Amplified Spontaneous Emission

Abstract

We demonstrate ultra-air- and photostable CsPbBr3 quantum dots (QDs) by using an inorganic-organic hybrid ion pair as the capping ligand. This passivation approach to perovskite QDs yields high photoluminescence quantum yield with unprecedented operational stability in ambient conditions (60 ± 5% lab humidity) and high pump fluences, thus overcoming one of the greatest challenges impeding the development of perovskite-based applications. Due to the robustness of passivated perovskite QDs, we were able to induce ultrastable amplified spontaneous emission (ASE) in solution processed QD films not only through one photon but also through two-photon absorption processes. The latter has not been observed before in the family of perovskite materials. More importantly, passivated perovskite QD films showed remarkable photostability under continuous pulsed laser excitation in ambient conditions for at least 34 h (corresponds to 1.2 × 10(8) laser shots), substantially exceeding the stability of other colloidal QD systems in which ASE has been observed.

Colloidal lead halide perovskite nanocrystals: synthesis, optical properties and applications

“…High PLQY is one of the main advantages of the colloidal perovskite NCs, prompting researchers to perform intensive investigations for their use as optical gain media for lasing. 13,34,36,37,[106][107][108] Zhu et al 13 have demonstrated wavelengthtunable lasing from single-crystalline organic-inorganic lead perovskite NWs with low thresholds (~220 nJ cm − 2 ) and high quality factors of Q~3600 (Figures 9a-c). The narrowing of the FWHM in the PL spectra by two orders of magnitude above an excitation fluence threshold presented a clear sign of lasing (Figure 9b).…”

“…Perovskite NCs have already shown great promise in many applications such as lasers, LEDs and photovoltaic devices. 10,23,[31][32][33][34][35][36][37][38] Even though the research on perovskite NCs is still in its starting stage, they are expected to have a significant role in the development of modern nanoscience and nanotechnology in the near future. This review provides an overview of the up-to-date developments in the synthesis of hybrid organicinorganic and all-inorganic perovskite NCs, their attractive optical properties and related emerging applications.…”

Perovskite Quantum Dot Light-Emitting Diodes

“…For example, to keep a high quantum yield, surface passivation is usually necessary, while long-chain ligands will reduce the conductivity of QDs. In this regard, Pan and coworkers applied a short ligand, di-dodecyl dimethyl ammonium bromide, to passivate CsPbBr 3 QDs and facilitate the carrier transport ability [37]. Consequently, a promoted PL quantum yield of about 71% was achieved, and a higher external quantum efficiency of ~3.0% was obtained.…”

Continuous-wave optically pumped green perovskite vertical-cavity surface-emitter

“…These approaches used hybrid perovskites in the form of powders with vertical cavities [10], cavity-free thin films [11,12], crystals with vertical cavities [13], microdisks/plates with whispering gallery modes (WGMs) [14,15], micro/nanowires with Fabry-Perot (FP) cavities [16,17] and gratings [18], micro/ nanorods with FP cavities [19], cavity-free colloidal quantum dots [20] and WGMs [21], colloidal nanocrystals with WGMs [22], FP cavities [23], and vertical cavities [24]. Compared to ASE, SE typically has a narrower linewidth and obvious threshold, and exhibits beam divergence and polarization [25].…”

“…All perovskites green-light emitters mentioned above [10,11,[13][14][15][16][17][18][19][20][21][22][23][24] were optically pumped using ultrashort pulses (typically, femtoseconds). An optically pumped NIR perovskite laser using longer pulses (nanoseconds) was recently demonstrated [26], but it was operated in a cryogenic environment.…”