Assessing the role of hydrogen in Fermi-level pinning in chalcopyrite and kesterite solar absorbers from first-principles calculations

AbstractThe promise enabled by boron arsenide’s (BAs) high thermal conductivity (κ) in power electronics cannot be assessed without taking into account the reduction incurred when doping the material. Using first principles calculations, we determine the κ reduction induced by different group IV impurities in BAs as a function of concentration and charge state. We unveil a general trend, where neutral impurities scatter phonons more strongly than the charged ones. CB and GeAs impurities show by far the weakest phonon scattering and retain BAs κ values of over ~1000 W⋅K−1⋅m−1 even at high densities. Both Si and Ge achieve large hole concentrations while maintaining high κ. Furthermore, going beyond the doping compensation threshold associated to Fermi level pinning triggers observable changes in the thermal conductivity. This informs design considerations on the doping of BAs, and it also suggests a direct way to determine the onset of compensation doping in experimental samples.

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The first principles calculations of Fermi level pinning in FUSI-PtSi/HfO2/Si system induced by local distortion of HfO2

10.7567/ssdm.2006.j-2-4 ◽

2006 ◽

Author(s):

Minoru Ikeda ◽

Georg Kresse ◽

Masaru Kadoshima ◽

Toshihide Nabatame ◽

Hideki Satake ◽

...

Keyword(s):

Fermi Level ◽

First Principles ◽

First Principles Calculations ◽

Fermi Level Pinning ◽

Local Distortion

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The magnetism of Fe4N/oxides (MgO, BaTiO3, BiFeO3) interfaces from first-principles calculations

RSC Advances ◽

10.1039/c4ra06763k ◽

2014 ◽

Vol 4 (90) ◽

pp. 48848-48859 ◽

Cited By ~ 9

Author(s):

Nan Feng ◽

Wenbo Mi ◽

Xiaocha Wang ◽

Haili Bai

Keyword(s):

Fermi Level ◽

First Principles ◽

First Principles Calculations ◽

Fermi Level Pinning ◽

P Type

n- and p-type doping of MgO are induced in contact with FeIFeII and (FeII)2N terminations of Fe4N, respectively. The metallic characteristics are induced in BaTiO3 by contact with FeIFeII termination, whereas p- and n-type doping appears in (FeII)2N/BaO and (FeII)2N/TiO2 interfaces, respectively. The interfacial dipole due to charge rearrangement may induce the Fermi level pinning in Fe4N/MgO and (FeII)2N/BaTiO3 interfaces. The deposition of Fe4N on BiFeO3 can result in a metallic BiFeO3.

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Dipole-induced Ohmic contacts between monolayer Janus MoSSe and bulk metals

npj 2D Materials and Applications ◽

10.1038/s41699-021-00253-w ◽

2021 ◽

Vol 5 (1) ◽

Author(s):

Ning Zhao ◽

Udo Schwingenschlögl

Keyword(s):

First Principles ◽

Ohmic Contacts ◽

Electrode Materials ◽

Electronic Device ◽

Two Dimensional ◽

First Principles Calculations ◽

Fermi Level Pinning ◽

Common Electrode ◽

Two Sides ◽

Metallic Electrodes

AbstractUtilizing a two-dimensional material in an electronic device as channel layer inevitably involves the formation of contacts with metallic electrodes. As these contacts can dramatically affect the behavior of the device, we study the electronic properties of monolayer Janus MoSSe in contact with different metallic electrodes by first-principles calculations, focusing on the differences in the characteristics of contacts with the two sides of MoSSe. In particular, we demonstrate that the Fermi level pinning is different for the two sides of MoSSe, with the magnitude resembling that of MoS2 or MoSe2, while both sides can form Ohmic contacts with common electrode materials without any further adaptation, which is an outstanding advantage over MoS2 and MoSe2.

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An effective and efficient approach to p-type AlN by Be2:O codoping from first-principles calculations

Modern Physics Letters B ◽

10.1142/s0217984916502572 ◽

2016 ◽

Vol 30 (20) ◽

pp. 1650257

Author(s):

Meng Zhao ◽

Wenjun Wang ◽

Jun Wang ◽

Junwei Yang ◽

Weijie Hu ◽

...

Keyword(s):

First Principles ◽

Ionization Energy ◽

Hole Concentration ◽

Valence Band Maximum ◽

First Principles Calculations ◽

Mutual Compensation ◽

Efficient Approach ◽

P Type ◽

Codoping Method

Various Be:O-codoped AlN crystals have been investigated via first-principles calculations to evaluate the role of the different combinations in effectively and efficiently inducing p-type carriers. It is found that the O atom is favored to bond with two Be atoms. The formed Be2:O complexes decrease the acceptor ionization energy to 0.11 eV, which is 0.16 eV lower than that of an isolated Be in AlN, implying that the hole concentration could probably be increased by 2–3 orders of magnitude. The electronic structure of Be2:O-codoped AlN shows that the lower ionization energy can be attributed to the interaction between Be and O. The Be–O complexes, despite failing to induce p-type carriers for the mutual compensation of Be and O, introduce new occupied states on the valence-band maximum (VBM) and hence the energy needed for the transition of electrons to the acceptor level is reduced. Thus, the Be2:O codoping method is expected to be an effective and efficient approach to realizing p-type AlN.

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Role of Dispersive Interactions in Determining Structural Properties of Organic–Inorganic Halide Perovskites: Insights from First-Principles Calculations

The Journal of Physical Chemistry Letters ◽

10.1021/jz5012934 ◽

2014 ◽

Vol 5 (15) ◽

pp. 2728-2733 ◽

Cited By ~ 149

Author(s):

David A. Egger ◽

Leeor Kronik

Keyword(s):

Structural Properties ◽

First Principles ◽

First Principles Calculations ◽

Halide Perovskites

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Computational and Experimental Insights into the Role of Acidic Molecules on the Corrosion Behavior on 7A46 Aluminum Alloy

Journal of Nanoscience and Nanotechnology ◽

10.1166/jnn.2021.19087 ◽

2021 ◽

Vol 21 (4) ◽

pp. 2221-2233

Author(s):

Yaru Liu ◽

Qinglin Pan ◽

Xiangdong Wang ◽

Ye Ji ◽

Qicheng Liu ◽

...

Keyword(s):

Corrosion Resistance ◽

Aluminum Alloy ◽

Corrosion Behavior ◽

First Principles ◽

First Principles Calculations ◽

Corrosive Media ◽

Corrosion Depth ◽

Corrosion Mechanisms ◽

Nanoscale Level

The corrosion mechanisms for different corrosive media on the aged 7A46 aluminum alloy were systematically investigated at nanoscale level. The combination of empirical intergranular and exfoliation corrosion behavior was employed, and coupled with first-principles calculations. Results revealed that the dispersed distribution of matrix precipitates (MPs) leads to the enhancement of the corrosion resistance pre-ageing (PA) followed by double-ageing (PA-DA) alloy. The deepest corrosion depth of PA-DA alloy was in hydrochloric acid, and the calculation result demonstrates that the passivation effect in combination with the accumulation of corrosion products in nitric acid protect the PA-DA alloy from further corrosion.

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Role of Surface Band Gap Widening in Cu(In, Ga)(Se, S)2 Thin-Films for the Photovoltaic Performance of ZnO/CdS/Cu(In, Ga)(Se, S)2 Heterojunction Solar Cells

MRS Proceedings ◽

10.1557/proc-763-b8.8 ◽

2003 ◽

Vol 763 ◽

Cited By ~ 4

Author(s):

U. Rau ◽

M. Turcu

Keyword(s):

Thin Films ◽

Surface Layer ◽

Solar Cells ◽

Fermi Level ◽

Band Gap ◽

Photovoltaic Performance ◽

Heterojunction Solar Cells ◽

Fermi Level Pinning ◽

Device Efficiency

AbstractNumerical simulations are used to investigate the role of the Cu-poor surface defect layer on Cu(In, Ga)Se2 thin-films for the photovoltaic performance of ZnO/CdS/Cu(In, Ga)Se2 heterojunction solar cells. We model the surface layer either as a material which is n-type doped, or as a material which is type-inverted due to Fermi-level pinning by donor-like defects at the interface with CdS. We further assume a band gap widening of this layer with respect to the Cu(In, Ga)Se2 bulk. This feature turns out to represent the key quality of the Cu(In, Ga)Se2 surface as it prevents recombination at the absorber/CdS buffer interface. Whether the type inversion results from n-type doping or from Fermi-level pinning is only of minor importance as long as the surface layer does not imply a too large number of excess defects in its bulk or at its interface with the normal absorber. With increasing number of those defects an n-type layer proofs to be less sensitive to material deterioration when compared to the type-inversion by Fermi-level pinning. For wide gap chalcopyrite solar cells the internal valence band offset between the surface layer and the chalcopyrite appears equally vital for the device efficiency. However, the unfavorable band-offsets of the ZnO/CdS/Cu(In, Ga)Se2 heterojunction limit the device efficiency because of the deterioration of the fill factor.

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Rich p -type-doping phenomena in boron-substituted silicene systems

Royal Society Open Science ◽

10.1098/rsos.200723 ◽

2020 ◽

Vol 7 (12) ◽

pp. 200723

Author(s):

Hai Duong Pham ◽

Wu-Pei Su ◽

Thi Dieu Hien Nguyen ◽

Ngoc Thanh Thuy Tran ◽

Ming-Fa Lin

Keyword(s):

Charge Transfer ◽

Fermi Level ◽

Charge Density ◽

Electronic Properties ◽

First Principles ◽

Chemical Environment ◽

First Principles Calculations ◽

Density Distributions ◽

Essential Properties ◽

P Type

The essential properties of monolayer silicene greatly enriched by boron substitutions are thoroughly explored through first-principles calculations. Delicate analyses are conducted on the highly non-uniform Moire superlattices, atom-dominated band structures, charge density distributions and atom- and orbital-decomposed van Hove singularities. The hybridized 2 p z –3 p z and [2s, 2 p x , 2 p y ]–[3s, 3 p x , 3 p y ] bondings, with orthogonal relations, are obtained from the developed theoretical framework. The red-shifted Fermi level and the modified Dirac cones/ π bands/ σ bands are clearly identified under various concentrations and configurations of boron-guest atoms. Our results demonstrate that the charge transfer leads to the non-uniform chemical environment that creates diverse electronic properties.

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The Role of Phase Stability in Ductile, Ordered B2 Intermetallics

MRS Proceedings ◽

10.1557/proc-980-0980-ii06-10 ◽

2006 ◽

Vol 980 ◽

Cited By ~ 5

Author(s):

James R. Morris ◽

Yiying Ye ◽

Maja Krcmar ◽

Chong Long Fu

Keyword(s):

Phase Stability ◽

First Principles ◽

Tensile Ductility ◽

Stacking Faults ◽

Low Energy ◽

First Principles Calculations ◽

Phase Competition ◽

Transformation Pathway ◽

Shape Memory Materials

AbstractWe discuss the underlying atomistic mechanism for experimentally observed large tensile ductility in various strongly ordered B2 intermetallic compounds. First-principles calculations demonstrate that all of the compounds exhibit little energy differences between the B2, B27 and B33 phases. These calculations relate observations of ductility in YAg, YCu and ZrCo to shape-memory materials including NiTi. One transformation pathway between the B2 and B33 phases establishes a connection between this phase competition, and stacking faults on the {011}B2 plane. The low energy of such a stacking fault will lead to splitting of the b=<100> dislocations into b/2 partials, observed in ZrCo, TiCo, and in the B19' phase of NiTi. Calculations demonstrate that this pathway is competitive with the traditional pathway for NiTi.

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