...
  • 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Journal of Materials Chemistry, A. Materials for energy and sustainability >Thermoelectric properties of Ag-doped Cu2Se and Cu2Te
【24h】

Thermoelectric properties of Ag-doped Cu2Se and Cu2Te

机译：Ag掺杂Cu2Se和Cu2Te的热电性能

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Cu2Se, Cu2Te and Ag-overstoichiometric compounds Cu_(1.98)Ag_(0.2)Se and Cu_(1.98)sAg_(0.2)Te were prepared by melting, annealing, followed by spark plasma sintering compaction. Low and high temperature thermoelectric properties were investigated by measuring the electrical conductivity, Seebeck coefficient, thermal conductivity and Hall coefficient between 2 K and 900 K. Structural analyses were performed by PXRD and SEM-EDX analyses. The Hall and Seebeck coefficients show that holes are the dominant carrier in all compounds. High temperature α-p phase transition in Cu2Se and Cu_(1.98)Ag_(0.2)Se between 350 and 400 K and multiple phase transitions (α-β, β-γ, γ~δ, δ-ε) in Cu2Te and Cu_(1.98)Ag_(0.2)Te between 350 K and 900 K were observed in measurements of heat capacity, temperature dependent PXRD data, and transport coefficients. Low temperature transport measurements (Hall coefficient, electrical conductivity, carrier mobility) strongly suggest the presence of yet another phase transition in Cu2Se, Cu_(1.98)Ag_(0.2)Se, and Cu_(1.98)Ag_(0.2)Te compounds at temperatures between 85 K and 115 K, reported here for the first time. Based on the transport data and structural analysis we conclude that doping Cu2Se and Cu2Te by Ag reduces the density of holes and strongly suppresses the thermal conductivity not only due to a smaller electronic contribution but also due to enhanced point defect scattering of phonons that reduces the lattice portion of the thermal conductivity. Moreover, the phase transition temperature is shifted to lower temperatures upon doping with Ag. The presence of Ag enhances thermoelectric performance of Cu2Te at all temperatures and Cu2Se benefits from Ag doping over a broad range of temperatures up to 700 K. The maximum ZT value of 1.2 at 900 K; 0.52 at 650 K; 0.29 at 900 K; and 1.0 at 900 K were achieved for Cu2Se, Cu_(1.98)Ag_(0.2)Se, Cu2Te and Cu_(1.98)Ag_(0.2)Te, respectively, between 2 K and 900 K.
机译：通过熔化，退火，随后进行电火花等离子烧结压制来制备Cu2Se，Cu2Te和Ag化学计量过量的化合物Cu_（1.98）Ag_（0.2）Se和Cu_（1.98）sAg_（0.2）Te。通过测量2 K和900 K之间的电导率，塞贝克系数，热导率和霍尔系数研究了高温和高温热电性能。通过PXRD和SEM-EDX分析进行了结构分析。霍尔和塞贝克系数表明，空穴是所有化合物的主要载体。 Cu2Se和Cu_（1.98）Ag_（0.2）Se在350和400 K之间发生高温α-p相变，Cu2Te和Cu_（）中发生多个相变（α-β，β-γ，γ〜δ，δ-ε）在热容量，温度相关的PXRD数据和传输系数的测量中，观察到350 K至900 K之间的1.98）Ag_（0.2）Te。低温迁移测量（霍尔系数，电导率，载流子迁移率）强烈表明，Cu2Se，Cu_（1.98）Ag_（0.2）Se和Cu_（1.98）Ag_（0.2）Te化合物中还存在另一个相变85 K和115 K，这是第一次报告。根据传输数据和结构分析，我们得出结论，Ag掺杂Cu2Se和Cu2Te会降低空穴的密度并强烈抑制导热性，这不仅是由于电子贡献较小，而且还因为声子的点缺陷散射增强，从而减少了晶格导热系数的一部分。此外，在掺杂Ag后，相变温度转变为较低的温度。 Ag的存在增强了在所有温度下Cu2Te的热电性能，而Cu2Se受益于在高达700 K的宽温度范围内进行Ag掺杂。900K时的最大ZT值为1.2。 650 K时为0.52; 900 K时为0.29; Cu 2Se，Cu_（1.98）Ag_（0.2）Se，Cu2Te和Cu_（1.98）Ag_（0.2）Te分别在2 K和900 K之间达到900 K和1.0 K.

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号