Institute of Applied Photophysics, Technische Universität Dresden, D-01062 Dresden, Germany.
J Phys Condens Matter. 2010 May 5;22(17):175506. doi: 10.1088/0953-8984/22/17/175506. Epub 2010 Apr 12.
The electrical resistance of stoichiometric and oxygen-deficient epitaxial 10 nm thick La(0.7)Ca(0.3)MnO(3) thin films on SrTiO(3) under photoexcitation covering the visible to the ultraviolet range has been investigated systematically as a function of illumination intensity, wavelength and temperature. In contrast to as-prepared films, the oxygen-deficient samples exhibit large photoconductivity of several orders of magnitude at low temperatures. By our detailed comparative analysis of the electrical conductivity of the film/substrate heterostructure and the bare substrate we are able to elucidate contributions of both carrier generation in the film and carrier injection from the substrate to the observed effect.
我们系统地研究了在 SrTiO3 上外延生长的具有化学计量比和缺氧的 10nm 厚 La(0.7)Ca(0.3)MnO(3) 薄膜在可见光到紫外光范围内的光激发下的电阻，作为光强、波长和温度的函数。与未处理的薄膜相比，缺氧样品在低温下表现出几个数量级的大光电导率。通过对薄膜/衬底异质结构和基底的电导率的详细比较分析，我们能够阐明薄膜中载流子的产生和基底中载流子的注入对观察到的效应的贡献。
