Abstract
Semiconductor perovskite films are now being widely investigated as light harvesters in solar cells with ever-increasing power conversion efficiencies, which have motivated the fabrication of other optoelectronic devices, such as light-emitting diodes, lasers, and photodetectors. Their superior material and optical properties are shared by the counterpart colloidal nanocrystals (NCs), with the additional advantage of quantum confinement that can yield size-dependent optical emission ranging from the near-UV to near-infrared wavelengths. So far, intensive research efforts have been devoted to the optical characterization of perovskite NC ensembles, revealing not only fundamental exciton relaxation and recombination dynamics but also low-threshold amplified spontaneous emission and novel superfluorescence effects. Meanwhile, the application of single-particle spectroscopy techniques to perovskite NCs has helped to resolve a variety of optical properties for which there are few equivalents in traditional colloidal NCs, mainly including nonblinking photoluminescence, suppressed spectral diffusion, stable exciton fine structures, and coherent single-photon emission. While the main purpose of ensemble optical studies is to guide the smooth development of perovskite NCs in classical optoelectronic applications, the rich observations from single-particle optical studies mark the emergence of a potential platform that can be exploited for quantum information technologies.
Highlights
Semiconductor perovskite films are being widely investigated as light harvesters in solar cells with ever-increasing power conversion efficiencies, which have motivated the fabrication of other optoelectronic devices, such as light-emitting diodes, lasers, and photodetectors
We focus on the optical studies of perovskite NCs with the quantum confinement in all three dimensions since those of perovskite nanowires and nanoplatelets are still at the infancy stage due to their unsatisfactory material and optical stabilities
Aside from the optical studies of perovskite NC ensembles for the good use of them in classical optoelectronic applications, the single-particle optical characterization is essential in uncovering intrinsic quantum-light characteristics that are increasingly required for investigating the artificial-atom physics and promoting the potential applications in quantum information technologies
Summary
The optoelectronic device applications of semiconductor perovskite NCs are based on their high-density ensemble films, whose optical characterization can provide valuable information on the optimization of relevant operation parameters. The time-resolved photoluminescence (PL) and transient absorption (TA) techniques can be employed to probe the carrier relaxation and recombination dynamics as well as the charge transport and extraction processes. Under both one- and multi-photon excitations of ultrafast laser pulses, amplified spontaneous emission (ASE) has been demonstrated in perovskite NC ensembles with the reported low thresholds being beneficial for the design of highly efficient laser devices. The ensemble perovskite NCs can interact with each other coherently via a common light field, the manipulation of which will promote the realizations of superfluorescent lasers and entangled multiphoton light sources
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
