全氧化物热电器件的制备及性能研究

Study on Fabrication and Properties of All-oxide Thermoelectric Devices

为了制备出具有一定实用性的热电器件,分别对Sm3+掺杂的p型Ca2Co2O5和n型CaMnO3氧化物热电材料进行研究。结果表明:Ca1.70Sm0.30Co2O5呈现层状结构,晶粒取向生长。Ca0.95Sm0.05MnO3为单一相正交晶系,陶瓷结构致密。两样品均具备良好的热电性能,Ca1.95Sm0.05Co2O5空穴导电,Ca0.95Sm0.05MnO3电子导电,功率因子均随温度的升高而增大,适合作为热电器件材料。利用这两种材料分别制备出四臂式和八臂式热电器件,并测试其性能,相同温差下八臂式器件的输出电压比四臂式器件高出2.7倍。

As part of the challenge to fabricate oxide thermoelectric devices, p-type Ca2Co2O5 and n-type CaMnO3 with Sm3＋ doped were investigated respectively. The textured Ca1.70 Sm0.30 Co2O5 exhibits lamellar structure and preferentially aligned along the pressing direction. Ca0.95 Sm0.05 MnO3 is a single phase with orthorhombic symmetry. The chemical reactions used to synthesize them were analyzed. The results show that Ca1.70Sm0.30Co2O5 is a p-type semiconductor, with holes conduction mechanism. Ca0.95 Sm0.05MnO3 is confirmed to be an n-type semiconductor, where the dominant current carriers are electrons. The power factor of both samples varies within narrow limits over the entire temperature range. Ca1.70Sm0.30Co2O5 and Ca0.95Sm0.05MnO3 show excellent thermoelectric performance. The thermoelectric devices with 4-legs and 8-legs based on this research were fabricated and the performance was tested. The results show that the voltage of 8-legs-device is 2.7 times higher than that of the 4-legs-device.