1. Enhancing the Sensitivity of GaN High Electron-Mobility Transistors-Based pH Sensor by Dual Function of Monolithic Integrated Planar Multi-Channel and Ultraviolet Light
- Author
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Xiaoli Wang, Jiapei Ao, Sichen Wu, Xin Li, Xianghong Yang, Long Hu, Chuanyu Han, and Weihua Liu
- Subjects
Materials science ,business.industry ,Photoconductivity ,Potassium hydrogen phthalate ,Transistor ,Gallium nitride ,Heterojunction ,High-electron-mobility transistor ,medicine.disease_cause ,Electronic, Optical and Magnetic Materials ,law.invention ,chemistry.chemical_compound ,chemistry ,law ,medicine ,Ultraviolet light ,Optoelectronics ,Electrical and Electronic Engineering ,business ,Ultraviolet - Abstract
In order to realize high-sensitivity real-time monitoring of acid-base neutral solutions in the industrial field, it is very important to study how to improve the sensitivity of a pH sensor. Herein, the sensitivity of the pH sensor was improved by using both monolithic integrated planar multi-channel and photoconductive properties of gallium nitride (GaN) high electron-mobility transistors (HEMTs) as a core of the pH sensor. The sensitive area of aluminum gallium nitride/gallium nitride (Al $_{0.25}$ Ga $_{0.75}$ N/GaN) heterojunction HEMT channel surface was increased, and the channel effective resistance was reduced by planar multi-channels. And the photogenerated current was generated by 365-nm ultraviolet (UV) light based on the photoconductive effect. This investigation mainly shows as the sensitivity of the tri-channel was 37.04 μA/pH, which increased 30 times compared with that of the single-channel device under the dual action of planar multi-channel and 365-nm UV light coupling in potassium hydrogen phthalate, mixed phosphate, and borax pH correction buffer solutions. The concept of using the GaN HEMT-based pH sensor for direct quantification of pH values in waste water provides a simple and high-performance method for industrial applications.
- Published
- 2021