Tuyển tập các báo cáo nghiên cứu khoa học trên tạp chí khoa học vật lý quốc tế đề tài: A HYDROGEN SENSITIVE Pd/GaN SCHOTTKY DIODE SENSOR | Journal of Physical Science Vol. 17 2 161-167 2006 161 A HYDROGEN SENSITIVE Pd GaN SCHOTTKY DIODE SENSOR . Hudeish1 2 and A. Abdul Aziz1 1School of Physics Universiti Sains Malaysia 11800 USM Pulau Pinang Malaysia 2Physics Department Hodeidah University Hodeidah Yemen Corresponding author lan@ Abstract In this work the forward current of Pd GaN Schottky diodes is found to increase significantly upon introduction of H2 into an N2 ambient. Analysis of the currentvoltage characteristics as a function of temperature shows that the current increase is due to a decrease in effective barrier height through a reduction in metal work function upon absorption of hydrogen. Experimental results also reveal that during the hydride formation process the forward current is increased by the increase of temperature for hydrogen. This work also demonstrates that the Schottky barrier height indeed increases with increasing temperatures and the resistance of the Pd n-GaN device decreases with increasing temperature. Keywords hydrogen sensor Schottky barrier height high temperature Schottky diodes 1. INTRODUCTION Micro chemical or biochemical sensors have become increasingly important subjects of research in the past several years as the need for chemical recognition elements and transducers grows. In addition much attention has been paid to the hydrogen sensing technology in harsh environment such as industrial manufacturing process protection of environment contamination and biomedical detection at high pressure and high temperature. These conditions has spurs the development of wide band gap semiconductor gas sensors because of their potential for high temperature operation chemical inertness and the ability to integrate them with power or microwave electrodes. Such high-temperature gas sensors can also be realized using wide-band-gap group-III nitride materials GaN AlN . Recently Pd-GaN Schottky diode has been shown to respond to hydrogen species. Palladium Pd is an .
