Schottky diode based on porous GaN for hydrogen gas sensing application

• Published in: Applied surface science Vol. 253; no. 24; pp. 9525 - 9528
• Main Authors: Yam, F.K., Hassan, Z.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 15.10.2007; Elsevier Science
• Subjects: Applied sciences; Condensed matter: electronic structure, electrical, magnetic, and optical properties; Cross-disciplinary physics: materials science; rheology; Electrical properties of specific thin films; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Electronics; Exact sciences and technology; General equipment and techniques; Hydrogen sensing; Iii-v semiconductors; Instruments, apparatus, components and techniques common to several branches of physics and astronomy; Interfaces; Materials science; Physics; Porous GaN; Porous materials; granular materials; Schottky barrier height; Semiconductor electronics. Microelectronics. Optoelectronics. Solid state devices; Sensors (chemical, optical, electrical, movement, gas, etc.); remote sensing; Specific materials; Surface barrier, boundary, and point contact devices; 81.05.Rm; 85.30.Hi; 73.40.Ei; Schottky barrier height; 73.61.Ey; Hydrogen sensing; Porous GaN; Porous GaN; Hydrogen sensing; Schottky barrier height; Inorganic compounds; Semiconductor materials; Gallium nitrides; Hydrogen; Porous materials; 73.40.Ei; 73.61.Ey; 81.05.Rm; 85.30.Hi; Measurement sensor; Schottky barrier diodes; Barrier height; Microstructure; Gas detector
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2007.05.071

This article reports the study of Pd Schottky contact on porous n-GaN for hydrogen gas sensing. Upon exposure to 2% H 2 in N 2, porous GaN sensor exhibited significant change of current. Morphological studies revealed that Pd contact deposited on porous GaN has ridge-trench-like morphology, a dense porous network was found in between the ridges. The dramatic change of current was attributed to the unique microstructure at Pd/porous GaN interface, which allowed higher accumulation of hydrogen; this resulted in a stronger effect of H-induced dipole layer and led to a significant change in the electrical characteristics of the porous sensor.