Film Thickness Dependence of Rectifying Properties of La1.85Sr0.15CuO4/Nb-SrTiO3 Junctions
CHEN Lei-Ming1,2, LI Guang-Cheng1, ZHANG Yan1, GUO Yan-Feng2
1Zhengzhou Institute of Aeronautical Industry Management. Zhengzhou, Henan 450015 2National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190
Film Thickness Dependence of Rectifying Properties of La1.85Sr0.15CuO4/Nb-SrTiO3 Junctions
CHEN Lei-Ming1,2, LI Guang-Cheng1, ZHANG Yan1, GUO Yan-Feng2
1Zhengzhou Institute of Aeronautical Industry Management. Zhengzhou, Henan 450015 2National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190
In this work, p-n junctions are made from directly depositing optimal doped La1.85Sr0.15CuO4 (LSCO) films on n-type Nb-doped SrTiO3 substrates. Film thickness controlled rectifying behaviors are strikingly displayed. The starting points of the diffusion voltage reduction Vd-on change clearly with varying film thickness. Vd-on and TC coincide with each other when the film thickness is larger than 300 nm, indicating a close relation between the two parameters. However, when the film is very thin (<350 nm) a departure between the two parameters was also observed. A possible reason for this is discussed within the framework of an inhomogeneous Schottky contact. Enhanced interface inhomogeneity due to the tensile strain appears to be the origin.
In this work, p-n junctions are made from directly depositing optimal doped La1.85Sr0.15CuO4 (LSCO) films on n-type Nb-doped SrTiO3 substrates. Film thickness controlled rectifying behaviors are strikingly displayed. The starting points of the diffusion voltage reduction Vd-on change clearly with varying film thickness. Vd-on and TC coincide with each other when the film thickness is larger than 300 nm, indicating a close relation between the two parameters. However, when the film is very thin (<350 nm) a departure between the two parameters was also observed. A possible reason for this is discussed within the framework of an inhomogeneous Schottky contact. Enhanced interface inhomogeneity due to the tensile strain appears to be the origin.
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2010, Vol. 27 
