Origin of the anomalous trends in band alignment of GaX/ZnGeX<sub>2</sub> (X = N, P, As, Sb) heterojunctions

Cao, Ruyue; Deng, Hui‐Xiong; Luo, Jun-Wei; Wei, Su‐Huai

doi:10.1088/1674-4926/40/4/042102

Cited by 11 publications

(3 citation statements)

References 27 publications

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“…Transition metal dichalcogenides (TMDs), such as MoSe 2 and WSe 2 , are promising candidates in novel high-performance nanoelectronic and optoelectronic devices due to their alluring properties. − In general, intrinsic defects and unintentional impurities during the growth of the materials are unavoidable, and they dramatically affect the physical and chemical properties of the materials. − On the other hand, the functionality of semiconductors depends essentially on whether enough free carriers can be introduced by doping. ,− Therefore, the prerequisite for designing and optimizing high-performance devices is to have deep understanding of the properties of defects in materials.…”

Section: Introductionmentioning

confidence: 99%

First-Principles Study of the Origin of the Distinct Conductivity Type of Monolayer MoSe₂ and WSe₂

et al. 2022

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Monolayer (ML) MoSe2 and WSe2 are promising materials for novel two-dimensional high-performance electronic and optoelectronic devices. Although ML MoSe2 and WSe2 possess the same crystal structure and similar chemical composition and band gap, they are experimentally observed to have distinct carrier types in conduction, i.e., ML MoSe2 is usually a n-type and ML WSe2 usually a p-type semiconductor. The reasons for such distinction are not fully understood so far. In this paper, by first-principles systematic investigation of the properties of intrinsic point defects and some inevitable unintentional extrinsic impurities under normal growth environments for ML MoSe2 and WSe2, we find that intrinsic defects are neither efficient p-type nor n-type dopants in these materials. Instead, hydrogen interstitial (H i inside ) is a shallow donor in both ML MoSe2 and WSe2, while nitrogen-substituting host selenium (N Se ) is a relatively shallow acceptor in both ML MoSe2 and WSe2. However, in the presence of both H and N doping, the compensation between the two type dopants pinned the Fermi energy close to the conduction band edge for ML MoSe2 and close to the valence band edge for ML WSe2. Our study, therefore, provides insights into the origin of the distinct types of conduction of ML MoSe2 and WSe2 and provides guidelines on how to dope transition metal dichalcogenides.

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Section: Introductionmentioning

confidence: 99%

First-Principles Study of the Origin of the Distinct Conductivity Type of Monolayer MoSe₂ and WSe₂

et al. 2022

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“…The ordered materials can have new and interesting optoelectronic properties, some of these associated with their lowered symmetry . One property of potentially significant impact on light emitters is the band offset between GaN and ZnGeN 2 , predicted to be as large as 1.0 eV in the conduction band and 1.1 eV in the valence band. − GaN and ZnGeN 2 have almost the same band gaps, around 3.4 eV, and lattice parameters that match to approximately 1% . Insertion of a thin layer of ZnGeN 2 into the active region of a III-nitride light-emitting diode structure has been predicted to increase the spontaneous emission rate for green (550 nm) emission by almost a factor of 5, compared to that of a conventional III-nitride structure, while desirably lowering the In content so that issues involving the large lattice mismatch are reduced. , …”

Section: Introductionmentioning

confidence: 99%

Metal–Organic Chemical Vapor Deposition of ZnGeGa₂N₄

Jayatunga

Karim

Lalk

et al. 2019

Crystal Growth & Design

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An alloy of ZnGeN 2 and GaN in equal proportions can form the octet-rule-preserving quaternary heterovalent nitride semiconductor ZnGeGa 2 N 4 . Singlecrystal films of the alloy targeting this composition were deposited on (11̅ 02) Al 2 O 3 (r-plane sapphire), (0001) Al 2 O 3 (c-plane sapphire), and (0001) GaN/Al 2 O 3 by metal−organic chemical vapor deposition using the precursors diethylzinc, germane, trimethylgallium, and ammonia. The growth directions were along the c-axis for films grown on the cplane sapphire and GaN templates, as well as along the orthorhombic [010] axis for films grown on r-plane sapphire. The effects of varying the growth temperature from 550 to 700 °C, choice of substrate, and trimethylgallium and germane flow rates on film composition and morphology were examined by Xray diffraction, field-emission scanning electron microscopy, and atomic force microscopy. The Zn/Ge atomic ratios were observed to decrease with growth temperature but increase with trimethylgallium flow rate. Growth rates, which varied with growth temperature from approximately 1 to 3.5 μm/h, were observed to increase with growth temperature up to 670 °C, then decrease abruptly with further increase in temperature. The growth rates were similar for growth on r-and c-plane sapphire substrates at the lower growth temperatures. However, above 650 °C the growth rates on c-and r-plane sapphire differed by as much as 70%. A broad photoluminescence double peak was observed only for samples grown on r-plane sapphire at the highest growth temperature. Hall measurements show n-type carrier concentrations in the mid-10 18 /cm −3 range and mobilities of a few cm 2 /V-s for material grown on r-sapphire substrates at 670 °C and above.

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“…第一性原理计算有助于从原子尺度理解和预测材料电学、光学、磁学等诸多性质, 近年来在半导体材料设计中正在发挥着越来越大的作用 [20,21] , 尤其对半导体光电子和微电子材料发展作出了重要贡献 [22] . 在半导体缺陷计算方面, 第一性原理计算同样发挥着不可取代的作用 [23] , 使我们在几乎不需要先验假设的情况下, 对缺陷的原子和电子结构产生清晰的认识, 既弥补了实验上缺陷分辨能力不足的短板, 辅助解释实验现象, 确定缺陷类型, 同时可以提供目前实验手段无法获得的数据, 完善人们对缺陷结构和性质的理解 [24][25][26] . 尽管第一性原理计算已经成为研究缺陷和杂质的有效方法, 目前该领域仍然存在诸多困难, 如带电缺陷的镜像电荷作用, 密度泛函近似造成的带隙误差等 [23] .…”

Section: 随着计算机技术的快速发展基于密度泛函理unclassified

A review of first-principles calculation methods for defects in semiconductors

Li,

Zhang,

Cai

et al. 2024

Acta Phys. Sin.

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Doping and defect control in semiconductors are essential prerequisites for their practical applications. First-principles defect calculations based on density functional theory offer crucial theoretical guidance for doping and defect control. This paper introduces the developments in the theoretical methods of first-principles semiconductor defect calculations. We will firstly introduce the method of the defect formation energy calculations, as well as finite-size errors to defect formation energies caused by the supercell method. We then present corresponding image charge correction schemes, which includes the widely used post-hoc corrections (such as Makov-Payne (MP), Lany-Zunger (LZ), Freysoldt-Neugebauer-Van de Walle(FNV) schemes), the recently developed self-consistent potential correction which performs the image charge correction in the self-consistent loop for solving Kohn-Sham equations, and the self-consistent charge correction scheme which does not require an input of macroscopic dielectric constants. Furthermore, we extend our discussions to charged defect calculations in low-dimensional semiconductors, elucidating the issue of charged defect formation energy divergence with increasing vacuum thickness under the jellium model, and introducing our theoretical model which fixes this energy divergence issue by placing the ionized electrons or holes in the realistic host band-edge states instead of the virtual jellium state. Then, we further provide a brief overview on defect calculation correction methods due to the DFT band gap error, including the scissors operator, LDA+U and hybrid functionals. Finally, to describe the defects formation energy calculations under illumination, we present our self-consistent two-Fermi-reservoirs model, which predicts well the defects and carrier concentrations under illumination in the Mg doped GaN system. This work summarizes the recent developments regarding first-principles defect calculations in semiconductors and might offer guidance for defect calculations in semiconductors especially low-dimensional ones, under both equilibrium and non-equilibrium conditions, aiding further advancements in doping and defect control within semiconductors.

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Origin of the anomalous trends in band alignment of GaX/ZnGeX₂ (X = N, P, As, Sb) heterojunctions

Cited by 11 publications

References 27 publications

First-Principles Study of the Origin of the Distinct Conductivity Type of Monolayer MoSe₂ and WSe₂

First-Principles Study of the Origin of the Distinct Conductivity Type of Monolayer MoSe₂ and WSe₂

Metal–Organic Chemical Vapor Deposition of ZnGeGa₂N₄

A review of first-principles calculation methods for defects in semiconductors

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Origin of the anomalous trends in band alignment of GaX/ZnGeX2 (X = N, P, As, Sb) heterojunctions

Cited by 11 publications

References 27 publications

First-Principles Study of the Origin of the Distinct Conductivity Type of Monolayer MoSe2 and WSe2

First-Principles Study of the Origin of the Distinct Conductivity Type of Monolayer MoSe2 and WSe2

Metal–Organic Chemical Vapor Deposition of ZnGeGa2N4

A review of first-principles calculation methods for defects in semiconductors

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Product

Resources

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Origin of the anomalous trends in band alignment of GaX/ZnGeX₂ (X = N, P, As, Sb) heterojunctions

First-Principles Study of the Origin of the Distinct Conductivity Type of Monolayer MoSe₂ and WSe₂

First-Principles Study of the Origin of the Distinct Conductivity Type of Monolayer MoSe₂ and WSe₂

Metal–Organic Chemical Vapor Deposition of ZnGeGa₂N₄