Synchrotron-based XPS studies of AlGaN and GaN surface chemistry and its relationship to ion sensor behaviour

Khir, Farah Liyana Muhammad; Myers, Matthew; Podolska, Anna; Sanders, Tarun M.; Baker, Murray V.; Nener, Brett; Parish, Giacinta

doi:10.1016/j.apsusc.2014.07.002

Cited by 36 publications

(9 citation statements)

References 33 publications

(41 reference statements)

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“…We carried out the X-ray photoelectron spectroscopy (XPS) for the bare AlN thin film as well as AlGaN eV in N 1s spectrum is due the Ga LMM Auger transition. [34][35][36][37] Therefore, the XPS study provides a supportive and substantiating evidence for the incorporation of Al in the proposed VS growth mechanism. The mean free path of the photoelectrons Al 2p, N 1s and Ga 3d is approximately 2 nm and the corresponding depth information is around 6 nm.…”

Section: The Elemental Analysis: X-ray Photoelectron Spectroscopysupporting

confidence: 59%

Piezoelectric domains in the AlGaN hexagonal microrods: Effect of crystal orientations

Sivadasan

Mangamma

Bera

et al. 2016

Journal of Applied Physics

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Presently, the piezoelectric materials are finding tremendous applications in the micro-mechanical actuators, sensors and self-powered devices. In this context, the studies pertaining to piezoelectric properties of materials in the different size ranges are very important for the scientific community. The III-nitrides are exceptionally important, not only for optoelectronic but also for their piezoelectric applications. In the present study, we synthesized AlGaN via self catalytic vapor-solid mechanism by atmospheric pressure chemical vapor deposition technique on AlN base layer over intrinsic Si(100) substrate. The growth process is substantiated using X-ray diffraction and X-ray photoelectron spectroscopy. The Raman and photoluminescence study reveal the formation of AlGaN microrods in the wurtzite phase and ensures the high optical quality of the crystalline material. The single crystalline, direct wide band gap and hexagonally shaped AlGaN microrods are studied for understanding the behavior of the crystallites under the application of constant external electric field using the piezoresponse force microscopy. The present study is mainly focused on understanding the behavior of induced polarization for the determination of piezoelectric coefficient of AlGaN microrod along the c-axis and imaging of piezoelectric domains in the sample originating because of the angular inclination of AlGaN microrods with respect to its AlN base layers.2

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Section: The Elemental Analysis: X-ray Photoelectron Spectroscopysupporting

confidence: 59%

Piezoelectric domains in the AlGaN hexagonal microrods: Effect of crystal orientations

Sivadasan

Mangamma

Bera

et al. 2016

Journal of Applied Physics

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“…No current studies have examined the stability and performance of the discussed III-nitride biosensors over such timeframes or in vivo. Publications are beginning to emerge on the role of oxide formation on the AlGaN/GaN sensor behavior (79). Coupling such studies with investigations of large sets of devices is essential for sensor optimization.…”

Section: Discussionmentioning

confidence: 99%

Electronic Biosensors Based on III-Nitride Semiconductors

Kirste

Rohrbaugh²,

Bryan³

et al. 2015

Annual Rev. Anal. Chem.

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We review recent advances of AlGaN/GaN high-electron-mobility transistor (HEMT)-based electronic biosensors. We discuss properties and fabrication of III-nitride-based biosensors. Because of their superior biocompatibility and aqueous stability, GaN-based devices are ready to be implemented as next-generation biosensors. We review surface properties, cleaning, and passivation as well as different pathways toward functionalization, and critically analyze III-nitride-based biosensors demonstrated in the literature, including those detecting DNA, bacteria, cancer antibodies, and toxins. We also discuss the high potential of these biosensors for monitoring living cardiac, fibroblast, and nerve cells. Finally, we report on current developments of covalent chemical functionalization of III-nitride devices. Our review concludes with a short outlook on future challenges and projected implementation directions of GaN-based HEMT biosensors.

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“…This produces an observable decrease in drain current. The charges induced by these events are by way of capacitive coupling and therefore are analogous to the application of a DC bias at the gate surface [4] [27]- [31]. The SAM layer consists of the crosslinker (DSP) and the immobilized antibody (Anti-MIG).…”

Section: Methodsmentioning

confidence: 99%

Characteristics of AlGaN/GaN HEMTs for Detection of MIG

Huq¹,

Trevino²,

Castillo³

2016

JMP

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The aim of this research work is to analyze the surface characteristics of an improved AlGaN/GaN HEMT biosensor. The investigation leads to analyze the transistor performance to detect human MIG with the help of an analytical model and measured data. The surface engineering includes the effects of repeatability, influence of the substrate, threshold shifting, and floating gate configuration. A numerical method is developed using the charge-control model and the results are used to observe the changes in the device channel at the quantum level. A Self-Assembled Monolayer (SAM) is formed at the gate electrode to allow immobilization and reliable crosslinking between the surface of the gate electrode and the antibody. The amperometric detection is realized solely by varying surface charges induced by the biomolecule through capacitive coupling. The equivalent DC bias is 6.99436 × 10 −20 V which is represented by the total number of charges in the MIG sample. The steady state current of the clean device is 66.89 mA. The effect of creation and immobilization of the protein on the SAM layer increases the current by 80-150 μA which ensures that successful induction of electrons is exhibited.

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Synchrotron-based XPS studies of AlGaN and GaN surface chemistry and its relationship to ion sensor behaviour

Cited by 36 publications

References 33 publications

Piezoelectric domains in the AlGaN hexagonal microrods: Effect of crystal orientations

Piezoelectric domains in the AlGaN hexagonal microrods: Effect of crystal orientations

Electronic Biosensors Based on III-Nitride Semiconductors

Characteristics of AlGaN/GaN HEMTs for Detection of MIG

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