TY - JOUR
T1 - Inhomogeneous barrier heights at dipole-controlled SrRuO3/Nb:SrTiO3 Schottky junctions
AU - Yajima, T.
AU - Minohara, M.
AU - Bell, C.
AU - Hwang, H. Y.
AU - Hikita, Y.
N1 - Funding Information:
This work was supported by the Department of Energy, Office of Basic Energy Sciences, Division of Materials Sciences and Engineering under Contract No. DE-AC02-76SF00515.
Publisher Copyright:
© 2018 Author(s).
PY - 2018/11/26
Y1 - 2018/11/26
N2 - It has recently been shown that the Schottky barrier height (SBH) formed at metal-semiconductor perovskite oxide heterojunctions can be dramatically tuned by the insertion of atomic-scale dipole layers at the interface. However, in idealized form, this would only allow for specific values of the SBH, discretized by the dipole layer thickness. Here, we examine the effect of fractional unit cell LaAlO3 dipoles inserted between SrRuO3 and Nb:SrTiO3 in (001) Schottky junctions, as a function of their in-plane lateral distribution. When the LaAlO3 dipoles are finely dispersed, we observe uniformly rectifying junctions, with SBHs reflecting the fractional LaAlO3 coverage. For larger length-scale distributions, the junction characteristics reflect the inhomogeneous combination of regions with and without the interface dipole. The characteristic length scale dividing the two regimes corresponds to the semiconductor depletion width scaled by the dipole potential, determining the effective scale for which the SBH can be continuously tuned.
AB - It has recently been shown that the Schottky barrier height (SBH) formed at metal-semiconductor perovskite oxide heterojunctions can be dramatically tuned by the insertion of atomic-scale dipole layers at the interface. However, in idealized form, this would only allow for specific values of the SBH, discretized by the dipole layer thickness. Here, we examine the effect of fractional unit cell LaAlO3 dipoles inserted between SrRuO3 and Nb:SrTiO3 in (001) Schottky junctions, as a function of their in-plane lateral distribution. When the LaAlO3 dipoles are finely dispersed, we observe uniformly rectifying junctions, with SBHs reflecting the fractional LaAlO3 coverage. For larger length-scale distributions, the junction characteristics reflect the inhomogeneous combination of regions with and without the interface dipole. The characteristic length scale dividing the two regimes corresponds to the semiconductor depletion width scaled by the dipole potential, determining the effective scale for which the SBH can be continuously tuned.
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U2 - 10.1063/1.5052712
DO - 10.1063/1.5052712
M3 - Article
AN - SCOPUS:85057571149
SN - 0003-6951
VL - 113
JO - Applied Physics Letters
JF - Applied Physics Letters
IS - 22
M1 - 221603
ER -