摘要
二维(2D)杂化钙钛矿铁电体的自发极化(P_(s))与光耦合作用有利于光生载流子分离,在光电器件方面显示出潜在的应用前景.然而,基于2D杂化钙钛矿铁电体组装的低检测限的偏振光检测器未见报道.本文基于2D杂化钙钛矿铁电体BA_(2)CsPb_(2)Br_(7)(BA为正丁胺)的高质量单晶,组装超灵敏的偏振光探测器.材料独特的双层钙钛矿结构产生较强的光学各向异性,沿不同晶轴方向的吸收比率高达α_(c)/α_(a)≈3.2(λ=405 nm).此外,铁电自发极化在极轴(c轴)方向产生较高的内建电场,有利于产生优异光电性能.在光强为40 n W/cm^(2)的辐射光下,晶体探测器表现出显著的二向色性比(电流比Iphc/Ipha≈1.5)、较高的响应度(~39.5 m A/W)和探测率(~1.2×10^(12)Jones),以及较短的响应时间(~300μs)与出色的抗疲劳性能.
Polarized-light photodetectors are the indispensable elements for practical optical and optoelectronic device applications.Two-dimensional(2D)hybrid perovskite ferroelectrics,in which the coupling of spontaneous polarization(P_(s))and light favors the dissociation of photo-induced carriers,have taken a booming position within this portfolio.However,polarized-light photodetectors with a low detectionlimit remain unexplored in this 2D ferroelectric family.In this work,the high-quality individual crystals of a 2D perovskite ferroelectric,BA_(2)CsPb_(2)Br_(7)(1,where BA^(+)is n-butylammonium),were used to fabricate ultrasensitive polarized-light detectors.Its unique bilayered structural motif results in quite strong electric and optical anisotropy with a large absorption ratio of a_(c)/α_(a)≈3.2(λ=405 nm).Besides,the presence of ferroelectric Psalso endows high built-in electric field along the polar c-axis that favors photoelectric activities.Under an extremely low detectable limit of 40 n W/cm^(2),the detector of 1 exhibits a notable dichroism ratio(I_(ph)^(c)/I_(ph)^(a)≈1.5),a large responsivity of~39.5 m A/W and a specific detectivity of~1.2×10^(12)Jones.Moreover,crystal-based devices of 1 also exhibit a fast response speed(~300μs)and excellent anti-fatigue merits.This work highlights great potentials of hybrid perovskite ferroelectrics toward polarized-light photodetection.
作者
王家棋
刘艺
韩世国
马钰
李耀斌
徐志云
罗军华
洪茂椿
孙志华
Jiaqi Wang;Yi Liu;Shiguo Han;Yu Ma;Yaobin Li;Zhiyun Xu;Junhua Luo;Maochun Hong;Zhihua Sun(College of Chemistry,Fuzhou University,Fuzhou 350116,China;State Key Laboratory of Structure Chemistry,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Sciences,Fuzhou 350002,China)
基金
supported by the National Natural Science Foundation of China(21622108,21875251,21525104,and 21833010)
the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB20010200)
Youth Innovation Promotion of Chinese Academy of Sciences。