摘要
利用脉冲激光沉积技术在SrTiO3单晶基片上制备了BiCuSeO薄膜并详细研究了沉积温度对薄膜晶体结构、微观形貌及热电输运性能的影响。在最佳沉积温度(330℃)下,所制备的BiCuSeO薄膜不含任何杂相且沿c轴取向外延生长,与基片的外延关系为[010]SrTiO3∥[010]BiCuSeO和[001]SrTiO3∥[100]BiCuSeO。电学性能测试表明该薄膜在20~350 K内均表现出金属导电特性,室温电阻率仅为12.5 mΩ·cm,远低于相应的多晶块体材料。计算所得的室温功率因子PF约为3.3μW·cm-1·K-2,高于相应的多晶块体材料,表明c轴取向BiCuSeO外延薄膜在薄膜热电器件领域具有重要的应用前景。
BiC uS eO thin films were prepared on single crystal SrT iO3 substrates by pulsed laser deposition,and the impact of deposition temperature on the crystal structure,micromophology and thermoelectric transport properties of the films was investigated in detail. At the optimal deposition temperature of 330 ℃,pure phase and c-axis oriented BiC uS eO thin films could be obtained,showing a epitaxial relationships between the substrates and the films of [010]SrT iO3∥[010]BiC uS eO and[001]SrT iO3∥[100]BiC uS eO. It could be found from the results of electrical properties test that the film exhibited a metallic-like conducting behavior over range of 20—350 K,with the room temperature resistivity of only 12.5 mΩ·cm,which was much lower than that of the corresponding polycrystalline bulk materials. The calculated room temperature power factor( PF) of the films was about 3.3 μW·cm-1·K-2,which was higher than that of the corresponding polycrystalline bulk materials,indicating a great application prospect of c-axis oriented BiC uS eO epitaxial thin films in the field of thin-film thermoelectric devices.
引文
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