Temperature-dependent polarity reversal inAu∕Nb:SrTiO3Schottky junctions

We have observed temperature-dependent reversal of the rectifying polarity in $\mathrm{Au}∕\mathrm{Nb}:\mathrm{Sr}\mathrm{Ti}{\mathrm{O}}_{3}$ Schottky junctions. By simulating current-voltage characteristics, we have found that the permittivity of $\mathrm{Sr}\mathrm{Ti}{\mathrm{O}}_{3}$ near the interface exhibits temperature dependence opposite to that observed in the bulk, significantly reducing the barrier width. At low temperature, tunneling current dominates the junction transport due both to such barrier narrowing and to suppressed thermal excitations. The present results demonstrate that junction properties can be dominated by the interface permittivity.

[1]  R. Stratton,et al.  Field and thermionic-field emission in Schottky barriers , 1966 .

[2]  A. Freeman,et al.  Charge compensation and mixed valency in LaAlO3 SrTiO3 heterointerfaces studied by the FLAPW method , 2006 .

[3]  Nevill Mott,et al.  Metal-Insulator Transition , 1968 .

[4]  J. H. Barrett Dielectric Constant in Perovskite Type Crystals , 1952 .

[5]  J. Schooley,et al.  SUPERCONDUCTIVITY IN SEMICONDUCTING SrTiO$sub 3$ , 1964 .

[6]  A. Millis,et al.  Lattice relaxation in oxide heterostructures: LaTiO3/SrTiO3 superlattices. , 2006, Physical review letters.

[7]  E. Sawaguchi,et al.  Dielectric Constant of Strontium Titanate at Low Temperatures , 1962 .

[8]  D. Muller,et al.  Lattice-polarization effects on electron-gas charge densities in ionic superlattices , 2006, cond-mat/0602045.

[9]  H. Okushi,et al.  The properties of a metal/oxide semiconductor junction prepared using a high‐purity ozone surface treatment , 1995 .

[10]  H. J. Hagger,et al.  Solid State Electronics , 1960, Nature.

[11]  Andrew G. Glen,et al.  APPL , 2001 .

[12]  Tetsuya Yamamoto,et al.  Fabrication and characterization of Ba1−xKxBiO3/Nb-doped SrTiO3 all-oxide-type Schottky junctions , 1997 .

[13]  Z. Šroubek Electron Tunneling and Band Structure of SrTi O 3 and KTa O 3 , 1970 .

[14]  M. Saifi,et al.  Dielectric Properties of Strontium Titanate at Low Temperature , 1970 .

[15]  K. Müller,et al.  SrTi O 3 : An intrinsic quantum paraelectric below 4 K , 1979 .

[16]  K. Ng,et al.  The Physics of Semiconductor Devices , 2019, Springer Proceedings in Physics.

[17]  Tetsuya Yamamoto,et al.  Temperature Dependence of the Ideality Factor of Ba1-xKxBiO3/Nb-doped SrTiO3 All-Oxide-Type Schottky Junctions , 1998 .

[18]  R. Aoki,et al.  Differential Capacitance of In-SrTiO3-x Contacts –Influence of the Electric-Field-Dependent Permittivity– , 1980 .

[19]  Akira Ohtomo,et al.  Artificial charge-modulationin atomic-scale perovskite titanate superlattices , 2002, Nature.

[20]  Nicola A. Spaldin,et al.  Origin of the dielectric dead layer in nanoscale capacitors , 2006, Nature.

[21]  Akira Ohtomo,et al.  A high-mobility electron gas at the LaAlO3/SrTiO3 heterointerface , 2004, Nature.