Characteristics of a new Pt/oxide/In0.49Ga0.51P hydrogen-sensing Schottky diode

A new Pt/oxide/InGaP metal-oxide semiconductor (MOS) Schottky diode has been fabricated and studied. Upon exposure to hydrogen, the steady-state and transient responses under different hydrogen concentrations and temperatures are measured. Due to the inherent property of InGaP material, e.g. the wide energy gap, a wide hydrogen-sensing range as large as 300 K (from room temperature to 600 K) is obtained. Even at room temperature, a very high sensitivity over 500% for 9090 ppm hydrogen in air is acquired. Furthermore, the measured absorption response time is less than 1 s at the applied voltage of 0.7 V and 9090 ppm hydrogen concentration atmosphere condition. Simultaneously, based on the analysis of the variation of barrier height and hydrogen coverage, the characteristics of the studied Pt/oxide/InGaP MOS Schottky diode is in good agreement with the Lundstrِm isotherm.