学术论文

      In掺杂对Cu2SnS3结构和电输运性能的影响

      Effects of In doping on the structure and electrical transport properties of Cu2SnS3

      摘要:
      通过固相合成法制备In掺杂p型Cu2SnS3的致密块体Cu2Sn1-xInxS3,考察其晶体结构和电输运特性.结果表明:In置换Sn引入空穴极大地提高电导率,且增加价带顶的简并度(三重),进而得到合适的赛贝克系数.x=0.20时Cu2Sn0.8In0.2S3的功率因子在673 K时达到0.75 mW/(m?K2).随着In掺杂量的增大,Cu2SnS3的晶体结构从有序的单斜相向无序的立方相和四方相结构转变,有效地抑制声子传播.利用理论最低晶格热导和Wiedemann-Franz定律计算的电子热导估算量纲为1的热电优值(ZT),在673 K时Cu2Sn0.8Zn0.2S3的ZT高达0.8,显示Cu2SnS3作为新型环保型热电材料的巨大潜力.
      Abstract:
      Dense bulk ceramics Cu2Sn1-xInxS3 of p-type In doping Cu2SnS3 were prepared by solid state reaction and investigated for structural and electrical transport properties.In-doping at the Sn-site markedly improved the electrical conductivity by implanting holes,with a modest Seebeck coefficient as favored by the triply degenerate state of valence band maximum.A maximum power factor of 0.75 mW/(m?K2) was obtained with x=0.20 of Cu2Sn0.8In0.2S3.The crystal structure of Cu2SnS3 transformed from original monoclinic to tetragonal via cubic symmetry with increasing amount of In,leading to an ordered-disordered change of the cations′ arrangement which would suppress the phonon transport effectively.A high ZT of 0.8 of Cu2Sn0.8In0.2S3 at 673 K was predicted by using the estimated total thermal conductivity based on a theoretical minimum lattice contribution and the Wiedemann-Franz relation,suggesting a great potential of Cu2SnS3 as an ecofriendly thermoelectric candidate.
      Author: SHEN Yawei PAN Lin WANG Yifeng
      作者单位: 南京工业大学 材料科学与工程学院,江苏南京,210009
      年,卷(期): 2017, 39(3)
      分类号: TQ125.1
      在线出版日期: 2017年7月3日
      基金项目: 国家自然科学基金,江苏高校优势学科建设工程