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Related papers: Two-dimensional GaAs/AlGaAs superlattice structure…

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We study the electronic and transport properties of a graphene-based superlattice theoretically by using an effective Dirac equation. The superlattice consists of a periodic potential applied on a single-layer graphene deposited on a…

Mesoscale and Nanoscale Physics · Physics 2015-02-26 Jonas R. F. Lima

The lead-free double perovskite material (viz. Cs$_2$AgBiCl$_6$) has emerged as an efficient and environmentally friendly alternative to lead halide perovskites. To make Cs$_2$AgBiCl$_6$ optically active in the visible region of solar…

Materials Science · Physics 2021-06-07 Deepika Gill , Preeti Bhumla , Manish Kumar , Saswata Bhattacharya

The specific rotational alignment of two-dimensional lattices results in a moir\'e superlattice with a larger period than the original lattices and allows one to engineer the electronic band structure of such materials. So far, transport…

Convergence of density-functional supercell calculations for defect formation energies, charge transition levels, localized defect state properties, and defect atomic structure and relaxation is investigated using the arsenic split…

Materials Science · Physics 2015-03-17 J T Schick , C G Morgan , P Papoulias

Multi-component chalcogenides, such as quasi-binary GeTe-Sb$_{2}$Te$_{3}$ alloys, are widely used in optical data storage media in the form of rewritable optical discs. Ge$_{2}$Sb$_{2}$Te$_{5}$ (GST) in particular has proven to be one of…

Materials Science · Physics 2015-09-29 Muneaki Hase , Paul Fons , Kirill Mitrofanov , Alexander V. Kolobov , Junji Tominaga

Influence of composition and external hydrostatic pressure on the structural, electronic, and optical properties of the CuGa1-xAlxS2 (x=0, 0.25, 0.5, 0.75, 1.0) chalcopyrite semiconductor was analyzed by means of the first-principles…

Materials Science · Physics 2013-09-13 M. G. Brik , C. G Ma

The lattice mismatch between AlGaN and AlN substrates limits the design and efficiency of UV LEDs, but it can be mitigated by the co-incorporation of boron. We employ hybrid density functional theory to investigate the thermodynamic,…

Materials Science · Physics 2020-01-08 Logan Williams , Emmanouil Kioupakis

Effect of geometrical and structural parameters on the efficiency of the tandem solar cell based on the III-V nanowire array on silicon is studied by the means of coupled opto-electrical simulations. A close to realistic structure,…

Cu-based chalcogenides are promising materials for thin-film solar cells with more than 20% measured cell efficiency. Using first-principles calculations based on density functional theory, the optoelectronic properties of a group of…

Materials Science · Physics 2016-09-21 Nasrin Sarmadian , Rolando Saniz , Bart Partoens , Dirk Lamoen

We use realistic pseudopotentials and a plane-wave basis to study the electronic structure of non-periodic, three-dimensional, 2000-atom (AlAs)_n/(GaAs)_m (001) superlattices, where the individual layer thicknesses n,m = {1,2,3} are…

mtrl-th · Physics 2016-09-07 K. A. Mader , L. -W. Wang , A. Zunger

Photogalvanic solar cells, the original dye based solar cell, have yet to fulfill their promise as a low fabrication cost, scalable energy conversion system. The efficient performance of photogalvanic cells relies on high dye solubility and…

Chemical Physics · Physics 2014-09-16 Mohammad Ali Mahmoudzadeh , John D. W. Madden

ScxAl1-xN is an emerging III-nitride material known for its high piezoelectric coefficient and ferroelectric properties. Integration of wide-bandgap ScxAl1-xN with GaN is particularly attractive for quantum photonic devices. Achieving low…

Materials Science · Physics 2025-07-15 Rajendra Kumar , Govardan Gopakumar , Zain Ul Abdin , Michael J. Manfra , Oana Malis

In this paper, we describe the design and characterization of 400-nm-long (88 periods) AlxGa1-xN/AlN (0 < x < 0.1) quantum dot superlattices deposited on self-assembled GaN nanowires for application in electron-pumped ultraviolet sources.…

Selenium is experiencing renewed interest as a promising candidate for the wide bandgap photoabsorber in tandem solar cells. However, despite the potential of selenium-based tandems to surpass the theoretical efficiency limit of single…

Dielectric and antiferroelectric materials are particularly promising for high-power energy-storage applications. However, relatively low energy density greatly hinders their usage in storage technologies. Here, we report…

Materials Science · Physics 2021-07-14 Zhijun Jiang , Bin Xu , Hongjun Xiang , L. Bellaiche

We consider quantum wire arrays consisting of GaAs rods embedded in Al$_{x}$Ga$_{1-x}$As and disposed in sites of a square or triangular lattice. The electronic and hole spectra around the conduction band bottom and the valence band top are…

Mesoscale and Nanoscale Physics · Physics 2015-05-14 M. Krawczyk , J. W. Klos

A detailed experimental analysis of the impact of active region design on the performance of 1300 nm lasers based on InGaAs/InAlGaAs superlattices is presented. Three different types of superlattice active regions and waveguide layer…

We have performed a numerical solution for band structure of an Abrikosov vortex lattice in type-II superconductors forming a periodic array in two dimensions for applications of incorporating the photonic crystals concept into…

Optics · Physics 2015-05-27 Alireza Kokabi , Hesam Zandi , Sina Khorasani , Mehdi Fardmanesh

Superlattices are promising low-dimensional nanomaterials for thermoelectric technology that is capable of directly converting low-grade heat energy to useful electrical power. In this work, the thermal conductivities of GaAs/Ge…

Mesoscale and Nanoscale Physics · Physics 2017-06-28 Roger Jia , Lingping Zeng , Gang Chen , Eugene A. Fitzgerald

Sulfide chalcopyrite Cu(In,Ga)S2 (CIGS) is a wide bandgap semiconductor suitable for the top cell of a tandem solar device. Here we demonstrate significant improvements in absorber quality by alloying with Ag to form (Ag,Cu)(In,Ga)S2…