Advances in the Application of Perovskite Materials

Nowadays, the soar of photovoltaic performance of perovskite solar cells has set off a fever in the study of metal halide perovskite materials. The excellent optoelectronic properties and defect tolerance feature allow metal halide perovskite to be employed in a wide variety of applications. This article provides a holistic review over the current progress and future prospects of metal halide perovskite materials in representative promising applications, including traditional optoelectronic devices(solar cells, light-emitting diodes, photodetectors, lasers), and cutting-edge technologies in terms of neuromorphic devices(artificial synapses and memristors) and pressure-induced emission. This review highlights the fundamentals, the current progress and the remaining challenges for each application, aiming to provide a comprehensive overview of the development status and a navigation of future research for metal halide perovskite materials and devices.

Single‑Layer ZnO Hollow Hemispheres Enable High‑Performance Self‑Powered Perovskite Photodetector for Optical Communication

The carrier transport layer with reflection reduction morphology has attracted extensive attention for improving the utilization of light.Herein,we introduced single-layer hollow ZnO hemisphere arrays(ZHAs)behaving light trapping effect as the electron transport layer in perovskite photodetectors(PDs).The singlelayer hollow ZHAs can not only reduce the reflection,but also widen the angle of the effective incident light and especially transfer the distribution of the optical field from the ZnO/FTO interface to the perovskite active layer confirmed by the 3D finitedifference time-domain simulation.These merits benefit for the generation,transport and separation of carriers,improving the light utilization efficiency.Finally,our optimized FTO/ZHA/CsPbBr3/carbon structure PDs showed high self-powered performance with a linear dynamic range of 120.3 dB,a detectivity of 4.2×10^(12) Jones,rise/fall time of 13/28μs and the f_(−3) dB of up to 28 kHz.Benefiting from the high device performance,the PD was demonstrated to the application in the directional transmission of encrypted files as the signal receiving port with super high accuracy.This work uniquely utilizes the features of high-performance self-powered perovskite PDs in optical communication,paving the path to wide applications of all-inorganic perovskite PDs.

Star perovskite materials

Nowadays,perovskite materials become research hot-spots with the soar of the power conversion efficiency(PCE)for perovskite solar cells.Specifically,metal halide per-ovskites(MHPs),with the formula ABX_(3)(A=CH_(3)NH_(3)^(+)(MA^(+)),CH(NH_(2))_(2)^(+)(FA^(+)),Cs^(+),etc.;B=Pb^(2+)or Sn^(2+);and X=I^(-),Cl^(-)and/or Br^(-)),have become star materials in optoelectronics.MHPs present favorable optoelectronic properties,like high absorption coefficient in visible range,long carrier diffusion length,high defect tolerance,and superior optical gain in a wide wavelength range.These merits gift MHPs promising potential in optoelectronic application,including solar cells,light-emitting diodes,photodetectors and lasers.This article introduces the star perovskite materials in milestone works and highlights the best-performing materials in respective op-toelectronic application.

Application of metal halide perovskite photodetectors

In recent years,metal halide perovskite materials have attracted wide attention in the fields of photovoltaics(PVs),light-emitting diodes(LEDs)and photodetectors(PDs)due to their excellent light absorption[1-6],adjustable bandgaps and long carrier diffusion length.Compared with commercial Si and GaN photodetectors,perovskite photodetectors(PPDs)present wider light detection range,higher sensitivity and higher external quantum efficiency(EQE)[7-9].

Perovskite films with gradient bandgap for self-powered multiband photodetectors and spectrometers

Bandgap-graded materials present varying spectral responses at different positions,making them possible to be used as an alternative to photoactive materials array in multi-spectral responsive devices,thus miniaturizing the apparatus.However,the preparation of bandgap-graded materials usually requires complicated deposition process.Here we report a facile lowtemperature solution process to make films with lateral bandgap gradients,which form spontaneously via self-spreading and interdiffusion of solutions.We show lead halide perovskite films with MAPbCl_(3)-MAPbBr_(3)and MAPbBr_(3)-MAPbI_(3)gradients,which exhibit light absorption onsets ranging from 410 to 781 nm.The bandgap-graded films were used to make self-powered multiband photodetectors,which show different spectral responses at different positions without applying bias voltage.Furthermore,self-powered spectrometers were made by using the multiband photodetectors.

Ultrasensitive,flexible perovskite nanowire photodetectors with long-term stability exceeding 5000 h

Photodetectors(PDs)based on perovskite nanowires are among the most promising next-generation photodetection technologies;however,their poor long-term stability is the biggest challenge limiting their commercial applica-tion.Herein,an ionic liquid,1-butyl-3 methylimidazolium tetrafuoroborate(BMIMBF_(4)),is incorporated as an additive into methylammonium lead tri-iodide(MAPbI_(3))nanowires;this not only effectively passivates defects to inhibit perovskite degradation but also leads to the formation of nanochannels,enabling fast charge transfer.As a result,the long-term stability and perfor-mance of MAPbI_(3)nanowires are considerably improved.The detectivity,linear detection range,and noise equivalent power of the MA PbI_(3)nanowire PD reach 2.06×10^(13)Jones,160dB,and 1.38×10^(-15)W Hz-^(1/2),respectively,compara-ble to the highest performance of perovskite nanowire PDs reported to date.Moreover,the unencapsulated PD can maintain 100%of its initial performance after being exposed to an open-air environment for more than 5000 h,esta-blishing it as the most stable perovskite nanowire PD reported to date.Nota-bly,the PD exhibits improved diffuse reflection imaging ability when compared with commercial silicon photodiode S2386.This study provides a new strategy for constructing sensitive,stable,and flexible perovskite PDs and will accelerate their commercial application in the future.

空间限域生长CsBi3I10无铅钙钛矿用于高质量、高灵敏度和高稳定性近红外光电探测器

因具有较高的耐热性和较长的电子扩散长度,无铅钙钛矿Cs Bi3I10备受关注.然而,由于二维结构Cs Bi3I(10)钙钛矿的表面极其粗糙且存在大量针孔,导致Cs Bi3I10钙钛矿器件性能不高.本文报道了一种利用空间限域生长(SCG)获得高平滑度、高结晶度和致密CsBi3I10钙钛矿薄膜的方法.相对于传统旋涂法制备的探测器,采用SCG方法获得的金属-半导体-金属结构Cs Bi3I10光电探测器(PDs)具有更高的光电流、更低的暗电流,以及更大的开/关比.此外,在长时间测试下,未封装的CsBi3I10钙钛矿PDs的光电流没有衰减;在空气中储存30天后,器件的性能也没有明显的退化,表现出了超高的稳定性.研究表明空间限域生长方法为制备高质量无铅钙钛矿开辟了一条新途径,有望在发光二极管、太阳能电池等领域得到应用.