砷锗镉晶体的生长和变温霍尔效应研究  

Growth and Temperature Dependent Hall Measurement of CdGeAs_(2) Crystal

作　　者：李佳樨 熊正斌 肖骁 刘心尧 余孟秋 陈宝军[1] 黄巍[1] 何知宇[1] LI Jiaxi;XIONG Zhengbin;XIAO Xiao;LIU Xinyao;YU Mengqiu;CHEN Baojun;HUANG Wei;HE Zhiyu(College of Materials Science and Engineering,Sichuan University,Chengdu 610064,China)

机构地区：[1]四川大学材料科学与工程学院,成都610064

出　　处：《人工晶体学报》2022年第2期193-199,共7页Journal of Synthetic Crystals

基　　金：四川省应用基础计划(2016JY0121)。

摘　　要：采用温度振荡法和改进的布里奇曼法进行了CdGeAs_(2)多晶合成与单晶生长,生长出∅28 mm×65 mm完整无开裂的CdGeAs_(2)单晶体。用金刚石外圆切割机切割出CdGeAs_(2)晶片,采用X射线衍射(XRD)和X射线能量色散谱仪(EDS)对合成的多晶粉末和切割出的晶片进行表征。结果表明,合成产物为单相四方黄铜矿结构的CdGeAs_(2)多晶,晶片的原子百分比接近于理想化学计量比。经傅里叶变换红外分光光度计测试发现,初生长的CdGeAs_(2)晶体在11.3μm处的吸收系数为0.117 cm^(-1),经过拟合计算得出禁带宽度为0.52 eV。通过变温(110~300 K)霍尔效应测试表明,CdGeAs_(2)晶体在110~300 K温度范围内都为p型导电,载流子浓度p_(H)和霍尔系数R_(H)随温度的升高分别升高和下降,而霍尔迁移率μ_(H)几乎不变。拟合计算出晶体中受主电离能E_(A)=0.305 eV,并进一步分析了生长晶体中可能存在的受主缺陷。CdGeAs_(2) polycrystalline was synthesized by temperature oscillation method,and an integral and crack-free CdGeAs_(2) single crystal with size of∅28 mm×65 mm was grown by the modified vertical Bridgman method.The synthesized polycrystalline was characterized by X-ray diffraction(XRD).The CdGeAs_(2) wafer cut with a diamond cylindrical cutter was characterized by energy dispersive spectrometer(EDS)and IR Prestige-21 spectrophotometer.The results show that the synthesized product is CdGeAs_(2) polycrystalline with tetragonal chalcopyrite structure,and the atomic percentage of the wafer is close to the ideal stoichiometric ratio.The absorption coefficient of the as-grown CdGeAs_(2) crystal at 11.3μm is 0.117 cm^(-1) and the fitted band gap is 0.52 eV.Temperature dependent(110 K to 300 K)Hall measurement shows that the sample is p-type conductive in the temperature range from 110 K to 300 K.The carrier concentration p_(H) increases and the Hall coefficient R_(H) decreases respectively with the increase of temperature,while the Hall mobility μ_(H) is almost unchanged.Fitting and calculating results show that the acceptor ionization energy E_(A) is 0.305 eV in the crystal,and the possible acceptor defects in CdGeAs_(2) single crystal was further analyzed.

关 键 词：半导体晶体 CdGeAs_(2)晶体 类籽晶技术 布里奇曼法 单晶生长 多晶合成 变温霍尔效应 红外透过谱 

分 类 号：O782[理学—晶体学]