摘要
Linearly bonded triiodide chains with fairly small distance between the adjacent iodine ions feature a facile electron transfer and highly anisotropic properties.Here,we demonstrate a novel strategy towards a new one-dimensional linear triiodide DMEDA·I6,using chain-type N,N'-dimethylethanediamine(DMEDA)cation to coordinate triiodine ions.This triiodide has the shortest distance between adjacent I3^- and good linearity.An estimated electronic band gap of1.36 e V indicates its semiconducting properties.100 fold differences both in polarization-sensitive absorption and effective mass were achieved by simulation,with directions parallel and perpendicular to the a-axis of DMEDA·I6.The DMEDA·I6 single crystal-based photodetectors show a good switching characteristic and a distinct polarization-sensitive photoresponse with linear dichroic photodetection ratio of about 1.9.Strongly anisotropic features and semiconducting properties of DMEDA·I6 make this triiodide system an interesting candidate for polarization related applications.
线性链状三碘化物的研究重点主要体现在两个方面:减小碘离子之间距离,有利于电子转移;提高碘离子排列线性度,可以实现强各向异性.本文采用了一种新策略,使用链状二胺(N,N'-二甲基乙二胺,DMEDA)阳离子与三碘化物离子配位,形成一维线性三碘化物DMEDA·I6.相较于之前报道的三碘化物,该三碘化物相邻I3^-离子之间的距离最短,具有较好的线性度;同时具有1.36 e V的电子带隙,具有半导体性能.理论模拟和实验表征都表明该化合物具有强的各向异性.模拟预测沿a轴和垂直于a轴的吸收差异以及电子和空穴有效质量的差异最多可达100倍.我们还基于DMEDA·I6构造了一个光电导探测器,并获得了低暗电流和各向异性的光响应.DMEDA·I6的强各向异性和半导体特性使其成为偏振探测相关应用的有利竞争者.
作者
Li Yao
Peng Xu
Wanru Gao
Junze Li
Liang Gao
Guangda Niu
Dehui Li
Shiyou Chen
Jiang Tang
姚利;许鹏;高婉如;李俊泽;高亮;牛广达;李德慧;陈时有;唐江(Wuhan National Laboratory for Optoelectronics and School of Optical and Electronic Information,Huazhong University of Science and Technology,Wuhan 430074,China;Research Institute for Magnetoelectronics&Weak Magnetic-field Detection,College of Science,China Three Gorges University,Yichang 443002,China;School of Optical and Electronic Information,Huazhong University of Science and Technology,Wuhan 430074,China;State Key Laboratory of Precision Spectroscopy,Key Laboratory of Polar Materials and Devices(MOE),and Department of Optoelectronics,East China Normal University,Shanghai 200241,China;Collaborative Innovation Center of Extreme Optics,Shanxi University,Taiyuan 030006,China)
基金
financially supported by the National Natural Science Foundation of China (51761145048, 61725401 and 61704097)
the Innovation Fund of WNLO and the 62th China Postdoctoral Science Foundation (2017M622418)
