Local structure of amorphous GaN1−xAsx semiconductor alloys across the composition range

Levander, A. X.; Yu, K. M.; Новиков, С. В.; Liliental‐Weber, Z.; Foxon, C.T.; Wu, Junqiao; Walukiewicz, W.

doi:10.1063/1.4812277

Cited by 6 publications

(2 citation statements)

References 29 publications

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“…For the films grown on Pyrex substrates, the composition range for amorphous alloys extends to x~0.1 [77]. The amorphous nature of these films were further confirmed by extended X-ray absorption fine structure measurements [78].…”

Section: Lt-mbe Grown Gan1-xasx Over the Entire Composition Rangementioning

confidence: 67%

Highly mismatched GaN_1−xSb_xalloys: synthesis, structure and electronic properties

Sarney

Новиков

et al. 2016

Semicond. Sci. Technol.

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Highly mismatched alloys (HMAs) is a class of semiconductor alloys whose constituents are distinctly different in terms of size, ionicity and/or electronegativity. Electronic properties of the alloys deviate significantly from an interpolation scheme based on small deviations from the virtual crystal approximation. Most of the HMAs were only studied in a dilute composition limit. Recent advances in understanding of the semiconductor synthesis processes allowed growth of thin films of HMAs under non-equilibrium conditions. Thus reducing the growth temperature allowed synthesis of group III-N-V HMAs over almost the entire composition range. This paper focuses on the GaNxSb1-x HMA which has been suggested as a potential material for solar water dissociation devices. Here we review our recent work on the synthesis, structural and optical characterization of GaN1-xSbx HMA. Theoretical modeling studies on its electronic structure based on the band anticrossing (BAC) model are also reviewed. In particular we discuss the effects of growth temperature, Ga flux and Sb flux on the incorporation of Sb, film microstructure and optical properties of the alloys. Results obtained from two separate MBE growths are directly compared. Our work demonstrates that a large range of direct bandgap energies from 3.4 eV to below 1.0 eV can be achieved for this alloy grown at low temperature. We show that the electronic band structure of GaN1-xSbx HMA over the entire composition range is well described by a modified the BAC model which includes the dependence of the host matrix band edges as well as the BAC model coupling parameters on composition. We emphasize that the modified BAC model of the electronic band structure developed for the full composition of GaNxSb1-x is general and is applicable to any HMA.

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Section: Lt-mbe Grown Gan1-xasx Over the Entire Composition Rangementioning

confidence: 67%

Highly mismatched GaN_1−xSb_xalloys: synthesis, structure and electronic properties

Sarney

Новиков

et al. 2016

Semicond. Sci. Technol.

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“…Extended X-ray absorption fine structure (EXAFS) analysis is ideally suited for this purpose, allowing for determination of local environment around the X-ray absorbing atoms. By analyzing oscillations in the normalized X-ray absorption data, , critical information can be extracted, such as local coordination number ( N ), interatomic distance to neighboring atoms ( r ), and the Debye–Waller disorder parameter (σ 2 ). Despite their adjacent atomic numbers, the K edge energies of Nb and Mo are widely separated by ∼1 keV (Nb = 18.99 keV and Mo = 20.01 keV), and this provides sufficient energy span to fully resolve their EXAFS oscillations in the postabsorption spectral region.…”

Section: Resultsmentioning

confidence: 99%

Doping against the Native Propensity of MoS₂: Degenerate Hole Doping by Cation Substitution

et al. 2014

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Layered transition metal dichalcogenides (TMDs) draw much attention as the key semiconducting material for two-dimensional electrical, optoelectronic, and spintronic devices. For most of these applications, both n- and p-type materials are needed to form junctions and support bipolar carrier conduction. However, typically only one type of doping is stable for a particular TMD. For example, molybdenum disulfide (MoS2) is natively an n-type presumably due to omnipresent electron-donating sulfur vacancies, and stable/controllable p-type doping has not been achieved. The lack of p-type doping hampers the development of charge-splitting p-n junctions of MoS2, as well as limits carrier conduction to spin-degenerate conduction bands instead of the more interesting, spin-polarized valence bands. Traditionally, extrinsic p-type doping in TMDs has been approached with surface adsorption or intercalation of electron-accepting molecules. However, practically stable doping requires substitution of host atoms with dopants where the doping is secured by covalent bonding. In this work, we demonstrate stable p-type conduction in MoS2 by substitutional niobium (Nb) doping, leading to a degenerate hole density of ∼ 3 × 10(19) cm(-3). Structural and X-ray techniques reveal that the Nb atoms are indeed substitutionally incorporated into MoS2 by replacing the Mo cations in the host lattice. van der Waals p-n homojunctions based on vertically stacked MoS2 layers are fabricated, which enable gate-tunable current rectification. A wide range of microelectronic, optoelectronic, and spintronic devices can be envisioned from the demonstrated substitutional bipolar doping of MoS2. From the miscibility of dopants with the host, it is also expected that the synthesis technique demonstrated here can be generally extended to other TMDs for doping against their native unipolar propensity.

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Interfacial thermal stability and band alignment of La2O3/Al2O3 nanolaminates deposited by atomic layer deposition

Fan

Liu

et al. 2017

J Mater Sci: Mater Electron

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Local structure of amorphous GaN1−xAsx semiconductor alloys across the composition range

Cited by 6 publications

References 29 publications

Highly mismatched GaN_1−xSb_xalloys: synthesis, structure and electronic properties

Highly mismatched GaN_1−xSb_xalloys: synthesis, structure and electronic properties

Doping against the Native Propensity of MoS₂: Degenerate Hole Doping by Cation Substitution

Interfacial thermal stability and band alignment of La2O3/Al2O3 nanolaminates deposited by atomic layer deposition

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Local structure of amorphous GaN1−xAsx semiconductor alloys across the composition range

Cited by 6 publications

References 29 publications

Highly mismatched GaN1−xSbxalloys: synthesis, structure and electronic properties

Highly mismatched GaN1−xSbxalloys: synthesis, structure and electronic properties

Doping against the Native Propensity of MoS2: Degenerate Hole Doping by Cation Substitution

Interfacial thermal stability and band alignment of La2O3/Al2O3 nanolaminates deposited by atomic layer deposition

Contact Info

Product

Resources

About

Highly mismatched GaN_1−xSb_xalloys: synthesis, structure and electronic properties

Highly mismatched GaN_1−xSb_xalloys: synthesis, structure and electronic properties

Doping against the Native Propensity of MoS₂: Degenerate Hole Doping by Cation Substitution