脉冲激光沉积法制备Bi_2Sr_2Co_2O_δ热电薄膜及其激光感生的热电电压效应  

Bi_2Sr_2Co_2O_δ Thermoelectric Thin Films Prepared by Pulsed Laser Deposition and Study on Laser Induced Thermoelectric Voltages Effect

作　　者：邹平[1] 李智东[1] 张辉[1,2] 赵昆渝[1] 张鹏翔[1,2] 

机构地区：[1]昆明理工大学材料与冶金工程学院,云南昆明650093 [2]昆明理工大学光电子新材料研究所,云南昆明650051

出　　处：《中国激光》2009年第8期2154-2157,共4页Chinese Journal of Lasers

摘　　要：采用脉冲激光沉积(PLD)法在倾斜Al_2O_3(0001)衬底上制备了Bi_2Sr_2Co_2O_δ(BSCO)系列热电薄膜,发现该类薄膜中有激光感生热电电压(LITV)效应。X射线衍射(XRD)谱显示Bi_2Sr_2Co_2O_δ热电薄膜沿c轴外延生长。采用标准四探针法测试了Bi_2Sr_2Co_2O_δ热电薄膜的电阻随温度的关系。结果表明所制备的Bi_2Sr_2Co_2O_δ热电薄膜在80～360 K范围内呈半导体导电特性。研究发现,在倾斜角度分别为10°和15°的倾斜衬底上制备的Bi_2Sr_2Co_2O_δ热电薄膜都存在一个最佳厚度,在这一厚度下可使激光感生热电电压(LITV)信号的峰值电压达到最大,分别为0.4442 V和0.7768 V。可以认为该激光感生热电电压信号是由Bi_2Sr_2Co_2O_δ薄膜面内和面间塞贝克系数张量的各向异性引起的。Bi2 Sr2Co2Oδ （BSCO） thin films were grown on Al2O3 （0001） substrates by pulsed laser deposition （PLD） technique. Laser induced thermoelectric voltage （LITV） effect was observed in those films on vicinal-cut substrate. The result of X-ray diffraction （XRD） showed that films on untilted Al2O3 （0001） substrates were c oriented. The temperature dependence of the electrical resistivity of films was measured by a standard four probes method, the result showed that films were semiconductor from 80 K to 360 K. The optimal film thickness was found in two tilted substrates with 10° and 15° angles, at which the peak voltage of LITV signals reach 0. 4442 V and 0. 7768 V respectively. The anisotropy of Seebeck coefficient lead to laser induced thermoelectric voltage signals

关 键 词：薄膜 Bi2Sr2Co2Oδ热电薄膜 激光感生热电电压 脉冲激光沉积 响应时间 

分 类 号：O484.42[理学—固体物理]