An a-SiGe:H phototransistor integrated with a Pd film on glass substrate for hydrogen monitoring

A novel a-SiGe:H optoelectronic hydrogen gas sensing device has been developed. The optoelectronic gas sensing device integrated a high optical gain a-SiGe:H optical sensor with a sputtered palladium (Pd) film on a glass substrate. Through the mechanism of the Pd film's transmitted optical power modulated with the H/sub 2/ concentration in atmosphere, the device can be operated at room temperature with a wider range (50 ppm to 133000 ppm) and faster response, in comparison to a conventional Pd catalytic type H/sub 2/ sensors, thus providing a good candidate for hydrogen monitoring.