GaN Thin Film Based Light Addressable Potentiometric Sensor for pH Sensing Application

Abstract

Gallium nitride (GaN) is a material with remarkable properties, including wide band gap, direct light emission and excellent chemical stability. In this study, a GaN-based light addressable potentiometric sensor (LAPS) with Si 3 N 4 50 nm as a sensing membrane is fabricated. By modulated optical excitation from an ultraviolet 365 nm light-emitting diode, the photoresponse characteristic and related pH sensitivity of the fabricated GaNbased LAPS is investigated. A Nernstian-like pH response with pH sensitivity of 52.29 mV/pH and linearity of 99.13% is obtained. These results of the GaN-based LAPS show great promise and it could be used as a single chemical sensor or integrated optoelectronic chemical sensor array for biomedical research with high spatial resolution.

On a GaN-based ion sensitive field-effect transistor (ISFET) with a hydrogen peroxide surface treatment

“…It could be observed that the influences of interfering N + and K + ions on the studied ISFET are negligible. Comparisons of pH sensing performance among Device A and previously reported works are listed in Table 2 [20][21][22][23][24][25][26]. Although the highest average sensitivity (54.88 mV/pH) of treated ISFET is not outstanding as compared to previous works, the pH sensing performance is remarkably enhanced (∼26% improvement) by a simple H 2 O 2 surface treatment.…”

Recent Developments in R.F. Magnetron Sputtered Thin Films for pH Sensing Applications—An Overview

“…On the other hand, electrochemical methods are typically straightforward and inherently quantitative, and require simpler operation and setups. Electrochemical methods, however, have downsides, such as long-term instability and vulnerability to electrode fouling, but nevertheless, they are the most commonly used methods for pH detection, whereby the potential (potentiometric) [20,21,[51][52][53][54][55][56], current (amperometric) [57][58][59][60][61][62][63], or charge in an electrochemical cell serve as the analytical signals. Indeed, the glass electrode is currently the most commonly used electrochemical sensor for potentiometric pH measurements.…”

The ethanol-sensing properties of porous GaN nanofibers synthesized by electrospinning

“…GaN is a wide-band-gap semiconductor (3.4 eV at 300 K), and it is known to be a promising material for chemical sensor applications with remarkable properties including excellent chemical stability and biocompatibility [12,13]. As was demonstrated, various reducing and oxidizing gases like carbon monoxide (CO), hydrogen (H 2 ), acetylene (C 2 H 2 ) and nitric oxides (NO and NO 2 ) can be tested using heterostructured GaN thin films [14][15][16], hydrogen (H 2 ) and nitrogen dioxide (NO 2 ) can be detected using GaN nanowires in previous researches [1,17,18].…”