Effect of annealing on chemical, structural and electrical properties of Au/Gd2O3/n-GaN heterostructure with a high-k rare-earth oxide interlayer

Prasad, C. V. R. K.; Reddy, M. Siva Pratap; Reddy, V. Rajagopal; Park, Chinho

doi:10.1016/j.apsusc.2017.09.016

Cited by 56 publications

(10 citation statements)

References 38 publications

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“…The stretching vibrations of -OH (3339 cm −1 ), C=C (1634 cm −1 ), C-O (1217 cm −1 ) and C-O-C (1054 cm −1 ) were discovered by an FTIR scan of GO. The PGO-Gd spectra displayed stretching vibrations at 3617 cm −1 (-OH), 1515 cm −1 (C=C), 1380 cm −1 (C-OH), and 1217 cm −1 (C-O-H) and Gd2O3 spectra observed Gd-O stretching (514 cm −1 ), and this is consistent with prior results [36]. Furthermore, the strong stretching peak at 710 cm −1 indicates Gd(OH)3 [39].…”

Section: Pgo-gd Structural Chracterizationsupporting

confidence: 91%

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Polyvinyl Alcohol Polymer Functionalized Graphene Oxide Decorated with Gadolinium Oxide for Sequestration of Radionuclides from Aqueous Medium: Characterization, Mechanism, and Environmental Feasibility Studies

et al. 2021

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Uranium (U(VI)) and thorium (Th(IV)) ions produced by the nuclear and mining industries cause water pollution, thereby harming the environment and human health. In this study, gadolinium oxide-decorated polyvinyl alcohol-graphene oxide composite (PGO–Gd) was developed using a simple hydrothermal process to treat U(VI) and Th(IV) ions in water. The developed material was structurally characterized by highly advanced spectroscopy and microscopy techniques. The effects of pH, equilibration time and temperature on both radionuclides (U(VI) and Th(IV)) adsorption by PGO–Gd were examined. The PGO–Gd composite adsorbed both metal ions satisfactorily, with adsorption capacities of 427.50 and 455.0 mg g−1 at pH 4.0, respectively. The adsorption properties of both metal ions were found to be compatible with the Langmuir and pseudo–second-order kinetic models. Additionally, based on the thermodynamic characteristics, the adsorption was endothermic and spontaneous. Furthermore, the environmental viability of PGO–Gd and its application was demonstrated by studying its reusability in treating spiked surface water. PGO–Gd shows promise as an adsorbent in effectively removing both radionuclides from aqueous solutions.

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Section: Pgo-gd Structural Chracterizationsupporting

confidence: 91%

“…In Figure 2a, the peak of C 1s signal is observed at 283.49 eV, and the signal at 529.37 eV is attributed to O 2− , which corresponds to GO [35]. The Gd 4d XPS plot indicates that the signal at 141.4 eV is attributed with Gd 3+ [36,37]. Hence, the XPS analysis confirmed the formation of PGO-Gd.…”

Section: Pgo-gd Structural Chracterizationmentioning

confidence: 73%

Polyvinyl Alcohol Polymer Functionalized Graphene Oxide Decorated with Gadolinium Oxide for Sequestration of Radionuclides from Aqueous Medium: Characterization, Mechanism, and Environmental Feasibility Studies

et al. 2021

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“…GaN is a wide direct band gap material that has excellent optical properties and good physical/chemical stability even at higher temperatures, offering a wide range of applications in electro-optoelectronic devices such as diodes, LEDs, photodiodes, and field-effect transistors. − Similar to a ZnO material, GaN has high-level piezoelectric properties owing to its non-centrosymmetric wurtzite crystal structure. The development of piezotronic sensors based on nanostructures and nano thin films has accelerated since the discovery of materials such as graphene .…”

Section: Introductionmentioning

confidence: 99%

Strain-Controlled Flexible Graphene/GaN/PDMS Sensors Based on the Piezotronic Effect

Puneetha

Mallem

Lee

et al. 2020

ACS Appl. Mater. Interfaces

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Using simple graphene transfer and the laser lift-off process for a non-centrosymmetric GaN layer on a flexible polydimethylsiloxane (PDMS) substrate, the piezotronic effect by strain-induced current−voltage measurements at the two end points is studied. By inducing compressive strain on the flexible graphene/GaN/PDMS sensor, the Schottky barrier between the graphene and GaN/PDMS heterojunction can be electromechanically modulated by the piezotronic effect. It is observed that the flexible graphene/GaN/PDMS sensor is sensitive to various applied compressive and tensile strains in the positive/ negative bias scans. The sensor is extremely sensitive to a compressive strain of −0.1% with a gauge factor of 13.48, which is 3.7 times higher than that of a standard metal strain gauge. Furthermore, the sharp response of the flexible graphene/GaN/ PDMS sensor under the −0.1% compressive strain is also investigated. The results of this study herald the development of commercially viable large-scale flexible/wearable strain sensors based on the strain-controlled piezotronic effect in future investigations.

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“…3a, c, the statistical analysis provides average barrier height values of 0.70 eV and 0.84 eV with normalization deviation of 0.02 eV and 0.08 eV for the Au/n-GaN SJ and Au/Fe 3 O 4 /n-GaN HJ, respectively. The barrier height estimated for the Au/Fe 3 O 4 /n-GaN HJ compared with that of the reported barrier height values obtained for the other devices in the literature, for instance, is 0.72 eV for Al/Fe 3 O 4 /p-Si junction [30], 0.88 eV for Au/Fe 3 O 4 /p-Si Schottky contacts [31], 0.82 eV for Au/CZTS/n-GaN HJ [32], 0.98 eV for Au/ Gd 2 O 3 /n-GaN HJ [33], 0.94 eV Au/ZrO 2 /n-GaN MIS junction (4) [34]. It is noted that the average barrier height difference between Au/n-GaN SJ and Au/Fe 3 O 4 /n-GaN HJ is 0.14 eV.…”

Section: Resultsmentioning

confidence: 96%

Statistical distribution of barrier heights, current conduction mechanism and voltage-dependent capacitance–frequency characteristics of Au/Fe3O4/n-GaN heterojunction

Uma

Reddy

2019

SN Appl. Sci.

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This work demonstrates the modification of electrical parameters of the Au/n-GaN Schottky junction (SJ) by a thin magnetite metal (Fe 3 O 4) interlayer in between the Au and n-GaN substrates. The current-voltage (I-V), voltage-dependent capacitance-frequency (C-f) and conductance-frequency (G-f) characteristics of the Au/Fe 3 O 4 /n-GaN heterojunction (HJ) are systematically studied. Using statistical analysis, the mean barrier heights and ideality factors are found to be 0.70 eV and 1.62 for the SJ and 0.84 eV and 1.87 for the HJ, respectively. It is noticed that the mean barrier height of Au/ Fe 3 O 4 /n-GaN HJ increases as compared that of the Au/n-GaN SJ, indicating the Fe 3 O 4 interlayer modified the barrier height. The SJ revealed a transition from Poole-Frenkel emission at low voltages to Schottky emission at high voltages. However, the HJ exhibited Schottky emission over whole voltage range. It is observed that the higher values of capacitance decrease at low frequencies that are attributed to the excess capacitance resulting from the interface states in equilibrium with the n-GaN which could respond the ac signal. The interface states density (N SS) and relaxation time (τ) of the Au/Fe 3 O 4 /n-GaN HJ are estimated from C-f plots, respectively. The N SS reveals that the interface states decrease with voltage from the bottom of the conduction band toward the mid-gap. Keywords Fe 3 O 4 interlayer • n-GaN substrate • Voltage-dependent C-f and G-f properties • Interface state density • Relaxation time

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Effect of annealing on chemical, structural and electrical properties of Au/Gd2O3/n-GaN heterostructure with a high-k rare-earth oxide interlayer

Cited by 56 publications

References 38 publications

Polyvinyl Alcohol Polymer Functionalized Graphene Oxide Decorated with Gadolinium Oxide for Sequestration of Radionuclides from Aqueous Medium: Characterization, Mechanism, and Environmental Feasibility Studies

Polyvinyl Alcohol Polymer Functionalized Graphene Oxide Decorated with Gadolinium Oxide for Sequestration of Radionuclides from Aqueous Medium: Characterization, Mechanism, and Environmental Feasibility Studies

Strain-Controlled Flexible Graphene/GaN/PDMS Sensors Based on the Piezotronic Effect

Statistical distribution of barrier heights, current conduction mechanism and voltage-dependent capacitance–frequency characteristics of Au/Fe3O4/n-GaN heterojunction

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