A novel Pt/In0.52Al0.48As Schottky diode-type hydrogen sensor

On the basis of a Pt/In0.52Al0.48As metal-semiconductor structure, a novel hydrogen sensor is fabricated and demonstrated. The studied Pt/In0.52Al0.48As Schottky diode-type hydrogen sensor exhibits significant sensing performance including high relative sensitivity ratio of about 2600% (under the 1% H-2/air gas and V-R = -0.5 V at 30 degrees C), large current variation of 310 MA (under the 1% H-2/air gas and V-R = -5 V at 200 degrees C), widespread reverse voltage regime (0 similar to -5 V), stable hydrogen-sensing current-voltage (I-V) curves, and fast transient response time of 1.5 s. The calculated Schottky barrier-height change and series-resistance variation, from the thermionic-emission model and Norde method, are 87.0 meV and 288 Omega, respectively (under the 1% H-2/air gas at 30 degrees C). The hydrogen concentrations and operating temperatures tested in this letter are in the range of 15 ppm-1% H-2/air and 30 degrees C-250 degrees C, respectively. Based on the excellent integration compatibility with InP-based electronic devices, the studied device provides the potentiality in high-performance sensor-array applications.