HYDROGEN-SENSITIVE NI SIO2 A-SI-H SCHOTTKY DIODES

Hydrogen-sensitive Schottky diodes of Ni/SiO2/a-Si:H (where a-Si:H is hydrogenated amorphous silicon) have been prepared. The structures exhibit good quality rectification characteristics with a reverse saturation current density J0 = 1.09 x 10(-8) A cm-2 and a quality factor of 1.49, typical of a Schottky barrier dominated by recombination in the depletion region. The structures display hydrogen sensitivity similar to those where palladium is used as the catalytic metal contact. We report the variation in the barrier height together with the response time of the effect as a function of hydrogen concentration and substrate temperature.