Confinement of Electrons at the LaInO3/BaSnO3 Heterointerface

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. The formation of a 2D electron gas at the heterointerface between the two insulating oxides LaInO3 and BaSnO3 is directly observed by C–V measurements. The heterostructure is grown under reduced lattice strain by using SrSnO3 covered NdScO3 substrate and the charge carriers are confined in a sheet of 2.5 nm thickness.