Coherent single-photon emission from colloidal lead halide perovskite quantum dots

Abstract

Chemically prepared colloidal semiconductor quantum dots have long been proposed as scalable and color-tunable single emitters in quantum optics, but they have typically suffered from prohibitively incoherent emission. We now demonstrate that individual colloidal lead halide perovskite quantum dots (PQDs) display highly efficient single photon emission with optical coherence times as long as 80 ps, an appreciable fraction of their 210 ps radiative lifetimes. These measurements suggest that PQDs should be explored as building blocks in sources of indistinguishable single photons and entangled photon pairs.Our results present a starting point for the rational design of lead halide perovskite-based quantum emitters with fast emission, wide spectral-tunability, scalable production, and which benefit from the hybrid-integration with nano-photonic components that has been demonstrated for colloidal materials. Tisdale.

Light Generation in Lead Halide Perovskite Nanocrystals: LEDs, Color Converters, Lasers, and Other Applications

“…The unique energy diagrams and the resulting high defect tolerance of LHP‐NCs result in superior optical and electrical characteristics even when LHP‐NCs are fabricated by a crude synthesis However, the low luminous efficiency of LHP‐NCs at low excitation densities suggests that there is still considerable loss from trap‐induced nonradiative recombination . Hence, the most efficient LHP‐NCs are crystalline and surrounded by passivating ligands …”

“…Light emission from lead halide perovskites (LHPs) was reported over a decade ago; however, weak emissions at room temperature hindered the application of LHPs in light‐emitting devices because LHPs did not show any electroluminescence at the time . In the past few years, LHPs have returned to the spotlight in the form of nanoscale emitters because of their superior features in light generation and resulting applications . Low‐cost solution processing techniques are used to fabricate LHP nanocrystals (LHP‐NCs), and impressive achievements have been made in using LHP‐NCs in high‐brightness light‐emitting diodes (LEDs) with high external quantum efficiency (EQE) and as color converters for lighting and full‐color displays that have a wide color gamut and near‐unity luminous efficiency .…”

“…In addition to applications based on efficient luminescence under low excitation density, LHP‐NCs exhibit optically pumped low‐threshold lasing and proof‐of‐principle electrically excited lasing . Nonclassic applications exploiting LHP‐NCs have been extended to the direct detection of ionizing radiation, e.g., X‐rays and γ‐rays in which high‐energy X‐ray photons are converted to bright visible light and to single photon emitters that can be used in quantum technologies for communication, metrology, and encryption …”

Controlled Growth of CH3NH3PbBr3 Perovskite Nanocrystals via a Water–Oil Interfacial Synthesis Method

“…[1] Much attention has been devoted to the synthesis chemistry [2] and the optoelectronic properties [3] of LHP NCs,p romoting the rapid development of their related applications. Herein, we develop aw ater-oil interfacial synthesis of MAPbBr 3 NCs (MA = CH 3 NH 3 + ), whichp rolongs the reaction time to tens of minutes.T his method makes it possible to monitor in situ the formation process of MAPbBr 3 NCs and observe successive spectral evolutions from 438 to 534 nm in asingle reaction by extending reaction time.T he implementation of this method depends on reducing the formation rate of PbBr 6 4À octahedra and the diffusion rate of MA.…”

“…[1] Much attention has been devoted to the synthesis chemistry [2] and the optoelectronic properties [3] of LHP NCs,p romoting the rapid development of their related applications. [1] Much attention has been devoted to the synthesis chemistry [2] and the optoelectronic properties [3] of LHP NCs,p romoting the rapid development of their related applications.…”