摘要
通过逆温结晶的方法制备了CH3NH3PbI3单晶,用扫描电子显微镜观察晶体形貌、X射线粉末衍射仪测量晶体结构、拉曼光谱仪测量晶体光谱。此外,通过X射线单晶衍射仪确定了晶面方向,分别沿平行和垂直于晶体c轴方向对晶体进行切割,经打磨、抛光后在其对应的晶面上蒸镀电极进而制备出基于CH3NH3PbI3单晶的光探测器。采用不同波长和偏振方向的激光照射光探测器的受光面后,测试了器件的光电特性。实验结果表明,当激光的电场分量E平行于晶体的晶轴时光探测器的光电流密度比电场分量E垂直于晶轴时(垂直样品)的光电流密度大两个数量级。通过计算得到,激光的电场分量E平行于晶体晶轴时,光探测器的光响应度(R)是垂直样品的58倍、光暗电流比(P)的10倍和外量子效率(EQE)的66倍。发现CH3NH3PbI3单晶的晶轴对晶体的光电性能影响很大。
The single crystal of CH3NH3PbI3 was obtained by reverse temperature crystallization. The crystal morphology was observed by scanning electron microscope, the crystal structure was measured by X-ray powder diffractometer, and the crystal spectrum was measured by Raman spectrometer. The direction of the crystal plane was determined by using X-ray single crystal diffractometer and cut along parallel or perpendicular to the c-axis of the crystal. A photodetector was prepared by plating an electrode on the corresponding crystal face after polishing. The light receiving surface of the photodetector was irradiated with laser of different wavelengths and polarization directions. The experimental results show that when the electric field component E of the laser was parallel to the optic axis of crystal, the photocurrent density was two orders of magnitude larger than that of the perpendicular condition. By calculation, the optical responsivity(R), light-dark current ratio(P) and external quantum efficiency(EQE) values of the electric field component E of the laser parallel to the crystal axis of photodetector were 58, 10 and 66 times of the perpendicular condition, respectively. It could be concluded that the crystal axis of the CH3NH3PbI3 single crystal had a great influence on the photoelectric properties of the crystal.
作者
张中赛
常海涛
王喆
孙士帅
邓家春
ZHANG Zhongsai;CHANG Haitao;WANG Zhe;SUN Shishuai;DENG Jiachun(School of Science, Tianjin University of Technology,Tianjin 300384,China)
出处
《功能材料》
EI
CAS
CSCD
北大核心
2019年第8期8178-8182,8190,共6页
Journal of Functional Materials
基金
国家自然科学基金资助项目(11504267,11504269)
天津市教育委员会科研项目(2017KJ238)
关键词
CH3NH3PbI3单晶
晶轴
光电流密度
光响应度
光暗电流比
外量子效率
CH3NH3PbI3 single crystal
crystal axis
photocurrent density
optical responsivity
light-dark current ratio
external quantum efficiency
