Tunable graphene/Indium Nitride heterostructure diode sensor

In this work, a graphene/InN thin film heterostructure based diode sensor is demonstrated. InN thin film is grown on GaN/sapphire substrate, and CVD grown graphene is then transferred on the device to make a graphene/InN diode structure. Electrical characterization of the device shows good rectifying behavior across the graphene/InN heterojunction. Preliminary experiments with trace amount of water and acetone vapors and NO₂ gas show highly promising results. It is observed that this sensor offers better sensitivity than simple graphene or InN based conductometric sensors, primarily because of the presence of a tunable Schottky barrier formed between graphene and InN that can be modulated by different analyte gas molecules.