Open AccessZinc Oxide Nanowire Field Effect Transistor Used as a pH Sensor
Author(s) -
ofo M.J. Ditshego,
AUTHOR_ID
Publication year - 2022
Publication title -
international journal of electrical and electronic engineering and telecommunications
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.171
H-Index - 6
ISSN - 2319-2518
DOI - 10.18178/ijeetc.11.2.162-166
Subject(s) - nanowire , field effect transistor , materials science , transistor , electrode , optoelectronics , threshold voltage , ion , zinc , layer (electronics) , field effect , voltage , sensitivity (control systems) , analytical chemistry (journal) , nanotechnology , chemistry , electrical engineering , electronic engineering , chromatography , organic chemistry , metallurgy , engineering
An ion sensitive field effect transistor can outperform conventional ion-selective electrodes. Thus, a zinc oxide (ZnO) nanowire field effect transistor (NWFET) pH sensor was fabricated and measured. The sensor contained a channel with 1.7×1018 cm-3 donor concentration and 100 ZnO nanowires in parallel, each with the following dimensions: 10 μm×120 nm×20 nm. The active channel is passivated with an 18 nm Al2O3 layer. The device was measured under a controlled environment with and without pH solutions. The pH range was 3–9 with a sensitivity of 2.48 mV to 10.3 mV. The voltage sensitivity translates to a percentage value of 15%. The measurements obtained before and after the pH solution treatment demonstrate the possibility of re-use of the device by rinsing and brushing the sensing layer.