Open AccessEnhanced hydrogen sensitivity of AlGaN/GaN heterojunction gas sensors by GaN‐cap layer
Author(s) -
Chung G.,
Cha H.Y.,
Kim H.
Publication year - 2018
Publication title -
electronics letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.375
H-Index - 146
eISSN - 1350-911X
pISSN - 0013-5194
DOI - 10.1049/el.2018.1167
Subject(s) - heterojunction , materials science , schottky diode , optoelectronics , hydrogen , schottky barrier , layer (electronics) , wide bandgap semiconductor , gallium nitride , barrier layer , diode , high electron mobility transistor , sensitivity (control systems) , nanotechnology , electronic engineering , transistor , electrical engineering , chemistry , voltage , organic chemistry , engineering
We fabricated Pt‐functionalised hydrogen gas sensors on AlGaN/GaN heterojunction platform and investigated the influence of GaN‐cap layer on the sensing characteristics. Pt‐Schottky diodes with GaN‐cap layer exhibited a larger change of Schottky barrier height than ones with no GaN‐cap layer when hydrogen gas was detected. Technology computer‐aided design simulation indicated that the increase of electron concentration at heterojunction can be magnified by a larger change of barrier height. The AlGaN/GaN FET‐type sensors with Pt catalyst on the gate area demonstrated significant enhancement of hydrogen gas sensitivity from 16 to 35% at 200°C when GaN cap layer was employed.