Conduction band offset at the InN∕GaN heterojunction

Abstract

The conduction-band offset between GaN and InN is experimentally determined. InN∕n-type GaN isotype heterojunctions grown by molecular beam epitaxy are observed to exhibit Schottky-junction like behavior based on rectifying vertical current flow. From capacitance-voltage measurements on the heterojunction, the Schottky barrier height is found to be ∼0.94eV. The photocurrent spectroscopy measurement by backside illumination reveals an energy barrier height of 0.95eV across the heterojunction, consistent with the capacitance measurement. By combining electrical transport, capacitance-voltage, and photocurrent spectroscopy measurement results, the conduction band offset between InN and GaN is estimated to be ΔEC=1.68±0.1eV.