Gallium nitride-based gas, chemical and biomedical sensors

Semiconductor-based sensors are widely used for applications in detection of particular gases and liquids, fire detection, liquid quality monitoring, biosensing and medical sensing. As an example, our group has installed hydrogen sensors at a car dealership in Orlando, FL, USA, that houses a fleet of hydrogen-fuelled buses. These sensors are platinum (Pt)-coated aluminum gallium nitride (AlGaN) or gallium nitride (GaN) differential diodes whose output can be remotely monitored via an Internet connection and which provide an alarm both locally and to phones of relevant personnel. A screen-shot of the output of the six detector array is shown in Fig. 1.