共掺杂Cu,Te后禁带宽度变窄对In_2Se_3基半导体热电性能的影响  

Effect of Band Gap Reduction on the Thermoelectric Properties of In_2Se_3 Based Semiconductors after Co-Doping of Cu and Te

作　　者：崔教林[1] 张晓军[2] 李奕沄 高榆岚[2] 

机构地区：[1]宁波工程学院,浙江宁波315016 [2]中国矿业大学,江苏徐州221116 [3]太原理工大学,山西太原030024

出　　处：《稀有金属材料与工程》2012年第12期2118-2122,共5页Rare Metal Materials and Engineering

基　　金：国家自然科学基金(50871056);国家"863"高科技计划项目(2009AA03Z322);浙江省自然科学基金(Y4100182);宁波市自然科学基金(2011A610093)

摘　　要：α-In2Se3是一类A2ⅢB3Ⅳ型宽带隙半导体材料。但在α-In2Se3化合物中共掺杂适量的Cu,Te后发现禁带宽度(Eg)变窄,Eg值由本征态时的1.32eV减小到1.14eV。掺杂后电学性能得到了大幅度的改善。最大功率因子由0.7610-4增大到2.810-4W·m-1·K-2;最大热电优值(ZT)从本征态时的0.25提高到0.63。高分辨电镜(HRTEM)观察结果表明,在未掺杂时,α-In2Se3呈现非晶状组织,共掺杂Cu,Te后,微结构则转变成明显的多晶组织。在温度高于500K时,掺杂后晶格热导率的适量提高与该微结构转变有直接联系。-In2Se3 is one of the A2ⅢB3Ⅳ type semiconductors with a wide band gap. A proper co-doping of Cu and Te leads to the formation of slab Cu2Se, which accounts for the reduction of band gap Eg , with its value decreasing from 1.32 eV for the intrinsic -In2Se3 to 1.14 eV. This reduction of band gap is responsible for the remarkable improvement in thermoelectric properties, with the maximum power factor p increasing from 0.76×10-4 to 2.8×10-4 W·m-1 ·K-2 and the highest ZT value from 0.25 to 0.63. A proper co-doping results in a change in morphology from the amorphous-like structure represented by In2Se3 to the visible polycrystalline form, observed using HRTEM, and this change is directly related to the moderate enhancement of lattice thermal conductivity above 500 K.

关 键 词：α-In2Se3基半导体 禁带宽度(Eg) 热电性能 

分 类 号：TN304[电子电信—物理电子学]