Role of GaN cap layer for reference electrode free AlGaN/GaN-based pH sensors

Parish, Giacinta; Khir, Farah Liyana Muhammad; Krishnan, N. Radha; Wang, Jianan; Krisjanto, Jonathan S.; Li, Haoran; Keller, S.; Mishra, Umesh K.; Baker, Murray V.; Nener, Brett; Myers, Matthew

doi:10.1016/j.snb.2019.02.039

Cited by 20 publications

(9 citation statements)

References 44 publications

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“…The AlGaN/GaN-based pH sensors electrode free with and without a GaN capping layer was investigated and reported by Parish et al [76,89]. In that study, the sensor exhibited a linear response towards pH variations when a GaN-capped heterostructure was used [89]. The study results showed that the difference in the response at low pH could be attributed to the difference in activity of surface donors (surface states) present for AlGaN/GaN heterostructures [89].…”

Section: Gan Nanowires Sensors Based Devicesmentioning

confidence: 88%

“…The study results showed that the difference in the response at low pH could be attributed to the difference in activity of surface donors (surface states) present for AlGaN/GaN heterostructures [89]. Moreover, the use of a GaN cap for electrochemical stabilization and degradation prevention at the surface means that the Coulombic interaction effects between the electrolyte and surface states are mitigated [89]. The study results showed that in the absence of a reference electrode, a linear response towards pH requires a GaN cap layer [89].…”

Section: Gan Nanowires Sensors Based Devicesmentioning

confidence: 94%

“…In that study, the sensor exhibited a linear response towards pH variations when a GaN-capped heterostructure was used [89]. The study results showed that the difference in the response at low pH could be attributed to the difference in activity of surface donors (surface states) present for AlGaN/GaN heterostructures [89]. Moreover, the use of a GaN cap for electrochemical stabilization and degradation prevention at the surface means that the Coulombic interaction effects between the electrolyte and surface states are mitigated [89].…”

Section: Gan Nanowires Sensors Based Devicesmentioning

confidence: 96%

“…Figure 46 shows the Variation of sensor current (Im) values obtained at bias voltage. The AlGaN/GaN-based pH sensors electrode free with and without a GaN capping layer was investigated and reported by Parish et al [76,89]. In that study, the sensor exhibited a linear response towards pH variations when a GaN-capped heterostructure was used [89].…”

Section: Gan Nanowires Sensors Based Devicesmentioning

confidence: 97%

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Review of GaN Nanowires Based Sensors

Nahhas¹

2020

AJN

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This paper presents a review of the recent advances of GaN based nanowires sensors. GaN has gained substantial interest in the research area of wide band gap semiconductors due to its unique electrical, optical and structural properties. GaN nanostructured material exhibits many advantages for nanodevices due to its higher surface-to-volume ratio as compared to thin films. GaN nanostructured material has the ability to absorb ultraviolet (UV) radiation and useful in many optical applications. Recently, GaN nanostructured based devices have gained much attention due to their various potential applications specially in nanowires sensors. GaN nanowires sensors have been used in many devices such as gas sensors, biosensors, and pressure sensors. The recent aspects of GaN based nanowires sensors are presented and discussed. The performance of several sensors based devices which have been demonstrated on GaN is reviewed. The structural, electrical, and optical properties are also reviewed.

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Section: Gan Nanowires Sensors Based Devicesmentioning

confidence: 88%

Section: Gan Nanowires Sensors Based Devicesmentioning

confidence: 94%

Section: Gan Nanowires Sensors Based Devicesmentioning

confidence: 96%

Section: Gan Nanowires Sensors Based Devicesmentioning

confidence: 97%

See 2 more Smart Citations

Review of GaN Nanowires Based Sensors

Nahhas¹

2020

AJN

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“…Various FET based biosensors [5]- [9] for detection of glucose [10], Lactic acid [11], [12], uric acid [1], [13], [14] and protein have been developed which are being used for monitoring food quality, environment management and biomedical applications [15]. Sensors based on MOSFET device have also been reported for detection of various other biomolecule species such as anthrax [4], glucose [5] and c-reactive protein [6].…”

Section: Introductionmentioning

confidence: 99%

Analytical Modeling and Simulation of AlGaN/GaN MOS-HEMT for High Sensitive pH Sensor

2021

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This paper presents an analytical model of AlGaN/GaN MOS-HEMT based pH sensor for the first time to determine pH of different electrolyte solutions. Gouy-chapman stern model has been used to calculate the surface charge density. The results obtained using analytical model have been verified and show good agreement with the simulated results. Cavity length, thickness of AlGaN barrier layer and Al composition have been optimized to improve the sensitivity of the device. It has been observed that the drain current and threshold voltage decreases with increase in pH of the electrolytic solutions. Proposed AlGaN/GaN MOS-HEMT sensor demonstrate a quick response to the pH changes. The maximum drain-on-sensitivity of the device is 132mA/mm-pH. Surface potential and threshold voltage sensitivity of 0.95mV/pH and 950mV/pH respectively have been obtained which is much higher than the Nernstian limit(59.2mV/pH).

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A Composition-Dependent Unified Analytical Model for Quaternary InAlGaN/GaN HEMTs for pH Sensing

Upadhyay

Chattopadhyay

2021

J. Electron. Mater.

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Role of GaN cap layer for reference electrode free AlGaN/GaN-based pH sensors

Cited by 20 publications

References 44 publications

Review of GaN Nanowires Based Sensors

Review of GaN Nanowires Based Sensors

Analytical Modeling and Simulation of AlGaN/GaN MOS-HEMT for High Sensitive pH Sensor

A Composition-Dependent Unified Analytical Model for Quaternary InAlGaN/GaN HEMTs for pH Sensing

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