학술논문
GaN Optical Devices Integrated With Sol-Gel Films for pH Detection
Document Type
Periodical
Source
IEEE Transactions on Electron Devices IEEE Trans. Electron Devices Electron Devices, IEEE Transactions on. 71(2):1226-1230 Feb, 2024
Subject
Language
ISSN
0018-9383
1557-9646
1557-9646
Abstract
Accurate pH measurement is essential in numerous applications; however, developing a compact pH-sensing unit with features of quick response, a wide measurement range, and high reliability remains a significant challenge. In this work, the miniaturized design and fabrication of a fully integrated device for pH detection are demonstrated. The capabilities of the GaN device in light emission and light detection are investigated, and the effectiveness of the sol-gel film in responding to pH changes is determined through optical reflectance spectroscopy. By using an optimized film thickness of $16 ~\mu \text{m}$ , the compact integrated device exhibits a highly linear response across a wide pH range of 5–13. Dynamic measurements confirm that the device can provide consistent, stable, and fast photocurrent responses within 3–5 s when testing various 1- $\mu \text{L}$ acid-base samples. The developed chip-scale device has appealing characteristics such as millimeter-scale size, short measurement time, low sample volume demands, and ease of use, which render it a viable candidate for pH detection applications.