Ultrafast Photoluminescence Properties Based On Inorganic Perovskite Micro/nanostructures

Perovskite materials are the compounds with the CaTiO₃ type crystal structure.Metal halide perovskites—emerged as functional energy materials—have shown outstanding performances in photovoltaics due to their broad-band light absorption,large oscillator strength,and excellent charge-transport properties.And they have been widely used in the fields of high-efficiency solar cells,multi-parameter light emitters and miniature multicolor lasers.However,few people have applied perovskite materials to the field of ultrafast information storage.This work studies the stimulated emission and cavity-enhanced superfluorescence effects based on all-inorganic perovskite micro/nanostructures.More,we also systematic study the ultrafast photoluminescence properties exhibited by the above effects.The high-bandwidth optical coding is realized based on the perovskite miniature laser,which prompt new applications in the field of optical information technology.First,the high-quality single-mode laser is realized based on a micro/sub-micronmeter spherical structure perovskite optical microcavity.The stimulated emission mechanism can accelerate transition rate of the particle radiation,but the ultra-fast photoluminescence radiation property is usually only characterized as an important characteristic of lasing radiation.This paper reports the application of lasing-mediated ultra-fast optical coding,and studies the photoluminescence lifetime of the radiation process,the ultra-fast response capability of polarization and the ability to contral the time-dynamic waveform by the two-photon nonlinear absorption.Combining these ultra-fast photoluminescence properties,we achieve the multi-parameter ultra-fast optical coding based on the different states of the radiative core,i.e.,the lasing status and the nonlasing case.This kind of microstructure with both light source and optical coding functions has the following superior performance.1)THz coding based on perovskite core satisfies the requirements of device miniaturization and integration.2)Multiple parameters are coded together to improve the discrimination and reliability of the ultrafast code sequence,and to support the error correction by checking the parameters in the coding set,such as the radiation intensity,the degree of optical polarization and the degree of coherence.3)The non-linear characteristics of the lasing core could be extensible by the double-layer coding,which further increases the information capacity of the high-bandwidth encoder through the upgrade from binary to ternary.Based on perovskite microstructure coding,it can produce coherent light-polarized pulse sequences,which can promote the development of perovskite-mediated optical microchips.In addition to perovskite materials,the paradigm—‘laser-induced ultrafast encoding'can be popularized and applied in many optical material systems.On the other hand,the multi-body cooperative quantum state of exciton ensemble is successfully prepared based on a perovskite quantum dot superlattice microcavity.The high-density exciton ensemble is introduced into the optical microcavities to control the ultrafast radiation of the exciton collective state,and that is the cavity-enhanced superfluorescence effect.The stimulated emission of excitonic quantum ensemble in a superlattice microcavity is demonstrated to not be limited by the classical population-inversion condition,leading to a picosecond radiative duration time to dissipate all of the in-phase dipoles.These novel phenomenas can attracte the attention of related research fields,such as:the fields of photovoltaics and coded information,miniature universal light sources,high-bandwidth information communication and sensors based on micro/nanostructures.