基于手性诱导自旋选择的高性能二维手性钙钛矿X射线探测器  

High-performance two-dimensional chiral perovskite X-ray detectors based on chirality-induced spin selectivity

作　　者：潘睿亨 刘雨桐 赵波[2] 汪永杰 汤仙童 周贤菊 李云龙[2] Ruiheng Pan;Yutong Liu;Bo Zhao;Yongjie Wang;Xiantong Tang;Xianju Zhou;Yunlong Li(School of Science,Chongqing University of Posts and Telecommunications,Chongqing 400065,China;Shenzhen Institute of Advanced Technology,Chinese Academy of Sciences,Shenzhen 518055,China)

机构地区：[1]重庆邮电大学理学院,重庆400065 [2]中国科学院深圳先进技术研究院,深圳518055

出　　处：《科学通报》2024年第35期5161-5172,共12页Chinese Science Bulletin

基　　金：国家自然科学基金(12404448,52203342,62304236);重庆市自然科学基金(CSTB2024NSCQ-MSX0734,CSTB2024NSCQ-MSX0739);重庆市教委科学技术研究计划(KJZD-K202300612);广东省自然科学基金(2022A1515011613,2021QN02Y300);中国科协青年人才托举工程(YESS20210285)资助。

摘　　要：手性钙钛矿在无外场(磁、光、电)条件下表现出独特的光学活性和自旋特性,包括圆二色性(circular dichroism,CD)、手性诱导自旋选择(chirality-induced spin selectivity,CISS)等,被广泛应用于三维显示、非线性光学、自旋电子学等领域,然而该材料在高性能X射线探测方面的应用研究较少.本工作中,我们生长了二维手性/非手性钙钛矿单晶((R/S/rac-NEA)_(2)PbBr_(4))(NEA=C_(12)H_(13)N),并利用该晶体制备了结构简单的直接型X射线探测器(C/(R/S/rac-NEA)_(2)PbBr_(4)/C).实验发现,(S-NEA)2PbBr4 X射线探测器的灵敏度高达2.87×10^(4)μC Gyair^(-1) cm^(-2),器件的暗电流及暗电流漂移值分别为0.15 nA和7.6×10^(-8) nA cm^(-1) s^(-1) V^(-1),载流子迁移率与其寿命的乘积可达5.85×10^(-4) cm^(2) V^(-1),离子迁移活化能为219 meV.而(rac-NEA)_(2)PbBr_(4) X射线探测器的灵敏度仅为7.41×10^(3)μC Gyair^(-1) cm^(-2).分析实验结果可知,(R/S-NEA)_(2)PbBr_(4)的CISS特性使激发态产生手性诱导自旋极化,X射线辐照下极化激子态被快速解离成大量自旋依赖的光生电荷载流子,导致自旋反平行电子-空穴电荷载流子之间的复合几率降低,器件的上、下电极可以有效提取自旋平行的电子-空穴电荷载流子,进而大幅提升X射线探测器的性能.本研究为开发低成本、高性能直接型手性钙钛矿X射线探测器提供了一定的理论指导和实验支撑.Organic-inorganic hybrid metal halide perovskite materials have shown enormous application values in the field of optoelectronics,such as light emitting,solar photovoltaic,laser,quantum communication,and 3D display.This is mainly owing to their unique crystal structures and excellent optoelectronic properties.Based on their tunable chemical composition and crystal structures,the two-dimensional chiral metal halide perovskite with a layered structure can be obtained by introducing chiral organic cations into the achiral inorganic frameworks,leading to the significant optical activities and spin properties of two-dimensional chiral metal halide perovskite in the absence of magnetic,optical,electrical fields,such as circular dichroism(CD),chirality-induced spin selectivity(CISS),etc.Thus,this kind of material is usually used in circularly polarized luminescence and detection,nonlinear optics,as well as spintronics,but its application research in high-energy X-ray detection remains unknown.In this work,we introduce chiral organic molecules(R/S-NEA=(R/S-C_(12)H_(13)N))and achiral organic molecules(rac-NEA)into the achiral inorganic octahedral frameworks(PbI6)to synthesize a two-dimensional chiral perovskite((R/S-NEA)_(2)PbBr_(4))and an achiral two-dimensional chiral perovskite((rac-NEA)_(2)PbBr_(4))single crystals,respectively.These crystals possess remarkable white flake-like shapes.Meanwhile,this single crystal can be used to fabricate a structurally simple direct X-ray detector(C/(R/S/rac-NEA)_(2)PbBr_(4)/C).We find that the sensitivity of X-ray detectors based on(S-NEA)_(2)PbBr_(4) crystal is as high as 2.87×10^(4)μC Gyair^(-1) cm^(-2),which is much higher than that of two-dimensional achiral metal halide perovskite polycrystalline X-ray detectors.Moreover,both the dark current and dark current drift values of the devices are only 0.15 nA and 7.6×10^(-8) nA cm^(-1) s^(-1) V^(-1),respectively.The product of carrier mobility and lifetime(μτ)can reach 5.85×10−4 cm^(2) V^(-1).The activation energy for ion migr

关 键 词：二维手性钙钛矿 圆二色性 手性诱导自旋选择 自旋依赖解离 X射线探测器 

分 类 号：TN3[电子电信—物理电子学]