Confinement of Electrons at the LaInO3/BaSnO3 Heterointerface

Abstract

The properties of the conductance at the LaInO3/BaSnO3 heterointerface are reported. The heterointerface is formed by covering the semi-insulating BaSnO3:La thin films with 10 nm LaInO3 films, which are all epitaxially grown on NdScO3 substrates. Structural properties of BaSnO3 thin films are investigated by means of X-ray diffraction and transmission electron microscopy and exhibit a threading dislocation density of 6 × 1010 cm−2. Via capacitance–voltage (C–V) measurements, clear evidence is present for the accumulation of electrons at the interface within 2.5 nm in the BaSnO3 layer, confirming the formation of a 2D electron gas (2DEG). Additionally, temperature dependent Hall effect measurements reveal a semiconducting behavior of the electron density of the 2DEGs. The room temperature mobility of 22 cm2 V−1 s−1 at an electron density of 4 × 1013 cm−2 is found to increase as the temperature decreases to 25 K.