化学溶液沉积Bi2Sr2Co2O8热电薄膜及其激光诱导电压效应研究

利用化学溶液沉积技术在LaAlO3（001）单晶基片上外延生长了Bi2Sr2Co2O8热电薄膜并对其激光诱导电压效应进行了研究．热电性能测试表明该外延薄膜的室温电阻率和塞贝克系数均可以和优质单晶样品相比拟．此外，实验发现当用308nm，532nm，1064nm及10．6gm的激光辐照生长在斜切LaAlO3上的Bi2Sr2Co2O8外延薄膜表面时，可以在薄膜中观测到很强的横向开路电压信号．分析认为当入射激光光子能量（308，532和1064nm激光输出）大于Bi2Sr2Co2O8禁带宽度时，在Bi2Sr2Co2O8外延薄膜中观测到的激光诱导横向开路电压信号源于该薄膜热电效应和光电效应的综合贡献；而当入射激光光子能量（10．6μm激光输出）小于Bi2Sr2Co208禁带宽度时，在Bi2Sr2Co2O8外延薄膜中观测到的激光诱导横向开路电压信号主要源于薄膜的热电效应．以上结果表明Bi2Sr2Co2O8热电薄膜不仅在热电器件领域而且在宽波段激光光探测器领域都具有潜在的应用前景．

Chemical solution deposition of Bi2Sr2Co2O8thermoelectric thin films and its laser-induced voltage effects investigation

Bi2Sr2Co2O8 thermoelectric thin films have been epitaxial growth on the LaAlO3 （001） single crystal substrates and its laser-induced voltage （LIV） effects have been investigated. The thermoelectric performance measurements indicate that the room temperature resistivity and seebeck coefficient of the epitaxial films are comparable to those of single crystals. In additon, large open-circuit voltage signals have been observed when the films on tilted LaAlO3 are irradiated by the laser pulses of 308 nm, 532 nm, 1064 nm and 10.6 μm. The above experimental results suggest that the Bi2Sr2Co2O8 thin films have great potential applications both in the thermoelectric devices and wide-band laser photodetectors.