电极低温退火对Cd_(0.9)Mn_(0.1)Te:In/V单晶探测器电学性能的影响  

Effect of Low-Temperature Annealing of Electrodes on Electrical Performance of Cd_(0.9)Mn_(0.1)Te:In/V Single Crystals Detectors

作　　者：栾丽君[1] 李龙 张頔 李国海 俞鹏飞 段理[1] LUAN Lijun;LI Long;ZHANG Di;LI Guohai;YU Pengfei;DUAN Li(School of Materials Science and Engineering,Chang'an University,Xi'an 710061,China)

机构地区：[1]长安大学材料科学与工程学院,西安710061

出　　处：《硅酸盐学报》2024年第5期1597-1607,共11页Journal of The Chinese Ceramic Society

基　　金：陕西省国际科技合作计划重点项目(2020KWZ-008);长安大学中央高校基本科研业务费专项资金(300102312401)。

摘　　要：碲锰镉(Cd_(1-x)Mn_(x)Te,CMT)是性能优异的室温核辐射探测材料。目前,熔体法生长的CMT单晶内部存在大量本征缺陷导致其光电性能较差且CMT探测器对γ射线和α粒子的探测效率较低。本工作采用Te溶液垂直Bridgman法生长In/V共掺杂的Cd_(0.9)Mn_(0.1)Te单晶体,晶体禁带宽度为1.524eV,红外透过率达67.3%。为提高CMT探测器效率,制备了Au、Al、Ag和In 4种不同金属电极的MSM型CMT探测器,并测试了不同电极的I-V特性。结果表明Au和In电极表现出最佳电学性能:欧姆系数分别为1.043和0.969,电阻率分别为4.783×10^(10)Ω·cm和4.119×10^(10)Ω·cm,百伏漏电流分别为5.958 nA和6.758 nA。为进一步提高Au和In电极CMT探测器的电学性能,在430 K以下的低温段进行电极退火实验,结果表明:Au电极在390 K温度下退火1 h百伏漏电流降至2.31 nA,α粒子(5.48 MeV)辐射下CMT探测器能量分辨率从26.7%提升至17.4%;In电极在350 K温度下退火1 h后百伏漏电流减小至6.18 nA,能量分辨率从27.4%提升至21.8%。Introduction Cadmium manganese telluride(Cd(1-x)Mn_(x)Te,CMT)is an ideal material for room-temperature radiation detectors,which can be widely used in the fields of medical tests,radiation detection,and astrophysics.The higher partial pressure of Cd during the growth of CMT single crystals by the Bridgman method leads to severe volatilization of Cd,which in turn produces a high density of intrinsic point defects,such as Cd vacancies.This reduces the resistivity of the crystal and alters the conductive type of the crystal,making it difficult for the crystal to meet the requirements for device preparation.In this paper,CMT crystals were grown by a vertical Bridgman method with Te solution.The compositions were co-doped with In/V at 10~(17)atom/cm^(3) to compensate for the Cd vacancies and increase the crystal resistivity.In addition,the electrical properties of Au,Ag,Al and In electrodes in contact with CMT semiconductors were also investigated.Methods Te(9N),Cd(9N),In(9N),Mn(5N),and V(5N)were used as raw materials in a pellet form(Sichuan Ehalf High Purity Materials Co.,China).Cd(0.9)Mn(0.1)Te single crystals co-doped with In and V(doping concentrations of 2×10^(17)atom/cm^(3) and 3×10^(17)atom/cm^(3),respectively)were grown by a vertical Bridgman method with Te solution.The grown ingots were 95 mm in length and 30 mm in diameter,and a diamond wire cutting machine was used to cut wafers with a thickness of 2 mm at the head,middle and tail of Cd(0.9)Mn(0.1)Te:In/V ingots,and further cut single crystals of 10 mm×10 mm×2 mm.The head,middle and tail single crystals of Cd(0.9)Mn(0.1)Te:In/V ingots were tested for the crystal structure by a model D/M-2500 X-ray diffractometer,respectively.The optical properties of crystals were determined by Fourier transform infrared spectroscopy and UV-visible-near-infrared spectroscopy.Four single-crystal samples in the middle of Cd(0.9)Mn(0.1)Te:In/V ingot were selected as CMT detector materials.Au,Ag,Al and In metal electrodes were deposited on the surface of the crystals by a

关 键 词：碲锰镉 单晶 布里奇曼法 核辐射探测器 

分 类 号：TG145[一般工业技术—材料科学与工程] TN304[金属学及工艺—金属材料]