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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
DOE OSTI2021

Emerging inorganic solar cell efficiency tables (version 2)

Abstract This paper presents the second version of the efficiency tables of materials considered as emerging inorganic absorbers for photovoltaic solar cell technologies. The materials collected in these tables are selected based on their progress in recent years, and their demonstrated potential as future photovoltaic absorbers. The first part of the paper consists of the guidelines for the inclusion of the different technologies in this paper, the verification means used by the authors, and recommendation for measurement best practices. The second part details the highest world-class certified solar cell efficiencies, and the highest non-certified cases (some independently confirmed). The third part highlights the new entries including the record efficiencies, as well as new materials included in this version of the tables. The final part is dedicated to review a specific aspect of materials research that the authors consider of high relevance for the scientific community. In this version of the efficiency tables, we are including an overview of the latest progress in quasi one-dimensional absorbers, such as antimony chalcogenides, for photovoltaic applications.

14 SOLAR ENERGY↗
DOE OSTI2022

P-type conductivity in Sn-doped Sb 2 Se 3

Abstract Antimony selenide (Sb 2 Se 3 ) is a promising absorber material for thin-film photovoltaics. However, certain areas of fundamental understanding of this material remain incomplete and this presents a barrier to further efficiency gains. In particular, recent studies have highlighted the role of majority carrier type and extrinsic doping in drastically changing the performance of high efficiency devices (Hobson et al 2020 Chem. Mater. 32 2621–30). Herein, Sn-doped Sb 2 Se 3 bulk crystals are shown to exhibit p-type conductivity using Hall effect and hot-probe measurements. The measured conductivities are higher than those achieved through native defects alone, but with a carrier density (up to 7.4 × 10 14 cm −3 ) several orders of magnitude smaller than the quantity of Sn included in the source material. Additionally, a combination of ultraviolet, x-ray and hard x-ray photoemission spectroscopies are employed to obtain a non-destructive depth profile of the valence band maximum, confirming p-type conductivity and indicating a majority carrier type inversion layer at the surface. Finally, these results are supported by density functional theory calculations of the defect formation energies in Sn-doped Sb 2 Se 3 , showing a possible limit on the carrier concentration achievable with Sn as a dopant. This study sheds light on the effectiveness of Sn as a p-type dopant in Sb 2 Se 3 and highlights avenues for further optimisation of doped Sb 2 Se 3 for solar energy devices.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Exploration for astromers near 132 Sn with the Canadian Penning Trap

Nuclear isomers can have significant impacts on astrophysical nucleosynthesis processes, with recent efforts demonstrating that the population of isomeric states with different half-lives may require separate treatment in reaction networks to accurately capture the differences in heating or in identifiable electromagnetic signals. Several potential so-called “astromers” in tin and antimony isotopes near doubly magic 132 Sn were identified and direct mass measurements of their ground and isomeric states were performed with the Canadian Penning Trap at Argonne National Laboratory's CARIBU facility, and their impact on astrophysical reaction rates and in reaction networks was calculated. Finally, it was found that 129⁢𝑔,𝑚 Sn , with measured mass excesses of −80593.2⁢(25) and −80557.4⁢(25) keV, respectively, and an excitation energy of 35.8(35) keV, behaves as an astromer during neutron capture in the 𝑖-process and in the 𝑟-process.

isomer decays↗
DOE OSTI2020

Thermal emittance and lifetime of alkali-antimonide photocathodes grown on GaAs and molybdenum substrates evaluated in a –300 kV dc photogun

In this work, Cs x K y Sb photocathodes grown on GaAs and molybdenum substrates were evaluated using a –300 kV dc high voltage photogun and diagnostic beam line. Photocathodes grown on GaAs substrates, with varying antimony layer thickness (estimated range from <20 nm to >1 um), yielded similar thermal emittance per rms laser spot size values (~0.4 mmmrad=mm) but very different operating lifetime. Similar thermal emittance was obtained for a photocathode grown on a molybdenum substrate but with markedly improved lifetime. For this photocathode, no decay in quantum efficiency was measured at 4.5 mA average current and with peak current 0.55 A at the photocathode.

43 PARTICLE ACCELERATORS↗
DOE OSTI2025

Weyl semimetal phases and intrinsic spin-Hall conductivity in SbAs ordered alloys

Here, using density functional theory calculations, we investigated possible Weyl semimetal (WSM) phases in antimony arsenide ordered alloys Sb 1-x ⁢As x (x=0, 1/6, 1/3, 1/2, 2/3, 5/6, 1). We find WSM phases for all As compositions of Sb 1-x ⁢As x with broken inversion symmetry, in contrast to Bi 1-x⁢ Sb x where only compositions x=1/2 and 5/6 were predicted to exhibit WSM phases. The WSM phases in Sb 1-x ⁢As x are characterized by the presence of 12 Weyl points, located within 55 meV from the Fermi level in the case of x = 1/2. The robust spin-orbit coupling strength and Berry curvature in these alloys produce large spin-Hall conductivity in the range of 176–602 ($\hslash$/e)(S/cm), comparable to that in the BiSb alloys. Finally, Sb 0.5 ⁢As 0.5 is predicted to be almost lattice matched to GaAs(111), with the Fermi level within the gap of the semiconductor, facilitating growth and characterization, and thus, offering promising integration with conventional semiconductors.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Recent Advancements in Reconfigurable mmWave Devices Based on Phase-Change and Metal Insulator Transition Materials

Chalcogenide Phase Change Materials (PCM) and metal insulator transition (MIT) materials are a group of materials that are capable of switching between low resistance and high resistance states. These emerging materials have been widely used in optical storage media and memory devices. Over the past recent years, there have been interests in exploiting the PCM and MIT materials, especially germanium antimony telluride (GST) alloys and vanadium dioxide (VO 2 ), for radio frequency (RF) applications. The PCM and MIT-based RF devices are expected to bridge the gap between semiconductor switches and microelectromechanical system (MEMS) switches as they combine the low insertion loss performance of MEMS technology and the small size and reliability performance of semiconductor technology. This article presents an overview of the PCM and MIT materials for RF circuits and discusses the recent advancements in reconfigurable millimeter-wave (mmWave) devices based on PCM and MIT materials in depth.

36 MATERIALS SCIENCE↗
DOE OSTI2026

Solid-phase heteroepitaxy of oriented Sb 2 Se 3 on GaAs for birefringent thin films

Here, we investigate the amorphous-to-crystalline transformation of antimony selenide (Sb 2 Se 3 ) on UHV-prepared GaAs (001) substrates. In the bulk orthorhombic form, Sb 2 Se 3 is a layered quasi-1D semiconductor with highly anisotropic properties of interest for optical and electronic devices. We find that an amorphous layer deposited by molecular beam epitaxy annealed at or above 230 °C yields a textured-epitaxial structure among some randomly oriented domains. The textured-epitaxial Sb 2 Se 3 grains are oriented with the covalently bonded “1D axis” constrained in-plane to GaAs [110] and with multiple van der Waals (hk0) orientations out-of-plane. The same texture was achieved exclusively without randomly oriented grains using continuous-wave laser radiation, highlighting the use of thermal and optical methods to yield anisotropic crystalline Sb 2 Se 3 films directly from the amorphous phase. Polarized reflectance and polarized microscopy confirm the unique state of in-plane birefringence in the crystallized thin film. Overall, we show that solid-phase heteroepitaxy provides additional pathways to the integration of low-symmetry chalcogenide semiconductors for demanding applications where the inherent anisotropy needs to be preserved.

Xiao, Kelly [Stanford Univ., CA (United States)] (↗
DOE OSTI2020

Role of Oxygen on Chemical Segregation in Uncapped Ge 2 Sb 2 Te 5 Thin Films on Silicon Nitride

Germanium antimony telluride has been the most used and studied phase-change material for electronic memory due to its suitable crystallization temperature, amorphous to crystalline resistance contrast, and stability of the amorphous phase. In this paper, the segregation of Ge in a Ge 2 Sb 2 Te 5 film of 30 nm thickness during heating inside the transmission electron microscope was observed and characterized. Furthermore, Ge 2 Sb 2 Te 5 film was deposited using sputtering on a Protochips Fusion holder and left uncapped in atmosphere for about four months. Oxygen incorporated within the film played a significant role in the chemical segregation observed which resulted in amorphous Ge-O island boundaries and Sb and Te rich crystalline domains. Such composition changes can occur when the phase-change material interfaces insulating oxide layers in an integrated device and can significantly impact its electrical and thermal properties.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2026

ssys

`ssys` is a Python toolkit for exact algebraic transformation of ordinary differential equation (ODE) models into canonical S-system or Generalized Mass Action (GMA) form. Given a model in Antimony or SBML format, `ssys` produces a mathematically equivalent representation. The transformation introduces auxiliary variables as needed to decompose a broad class of nonlinearities into products of power-law terms. The recast is exact: the original and transformed systems have identical dynamics on the invariant constraint manifold defined by auxiliary variable definitions, given consistent initial conditions.

Hlavacek, William [Los Alamos National Laboratory]↗
DOE OSTI2022

Dynamically tunable second-harmonic generation using hybrid nanostructures incorporating phase-change chalcogenides

Nonlinear metasurfaces with high conversion efficiencies have been vastly investigated. However, strong dynamic tunability of such devices is limited in conventional passive plasmonic and dielectric material platforms. Germanium antimony telluride (GST) is a promising phase-change chalcogenide for the reconfiguration of metamaterials due to strong nonvolatile changes of the real and imaginary parts of the refraction index through amorphous-crystalline phase change. The orderly structured GST has an even higher potential in tunable second-harmonic generation (SHG) with a non-centrosymmetric crystal structure at the crystalline phase, while the amorphous phase of GST does not exhibit bulk second-order nonlinearity. Here, we experimentally demonstrate SHG switches by actively controlling the crystalline phase of GST for a GST-based hybrid metasurface featuring a gap-surface plasmon resonance, and a quarter-wave asymmetric Fabry–Perot (F–P) cavity incorporating GST. We obtain SHG switches with modulation depths as high as ~ 20 dB for the wavelengths at the on-state resonance. We also demonstrate the feasibility of multi-level SHG modulation by leveraging three controlled GST phases, i.e., amorphous, semi-crystalline, and crystalline, for the gap-surface plasmon hybrid device, which features stronger light–matter interaction and has higher resonant SHG efficiencies than the asymmetric F–P cavity device at respective GST phases. This research reveals that GST-based dynamic SHG switches can be potentially employed in practical applications, such as microscopy, optical communication, and photonic computing in the nonlinear regime.

42 ENGINEERING↗
DOE OSTI2020

Materials Data on Ba2YbSbO6 by Materials Project

Yb(BaO3)2Sb is High-temperature superconductor-derived structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional and consists of four antimony molecules, four ytterbium molecules, and one BaO3 framework. In the BaO3 framework, Ba2+ is bonded to six equivalent O2- atoms to form corner-sharing BaO6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Ba–O bond lengths are 2.33 Å. O2- is bonded in a linear geometry to two equivalent Ba2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba2YSbO6 by Materials Project

Ba2YSbO6 is alpha Rhenium trioxide-derived structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional and consists of four antimony molecules, four yttrium molecules, and one BaO3 framework. In the BaO3 framework, Ba2+ is bonded to six equivalent O2- atoms to form corner-sharing BaO6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Ba–O bond lengths are 2.34 Å. O2- is bonded in a linear geometry to two equivalent Ba2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on ZnTeO3 by Materials Project

ZnTeO3 is Antimony trioxide-derived structured and crystallizes in the orthorhombic Pbca space group. The structure is three-dimensional. Zn2+ is bonded to five O2- atoms to form a mixture of distorted corner and edge-sharing ZnO5 trigonal bipyramids. There are a spread of Zn–O bond distances ranging from 2.00–2.31 Å. Te4+ is bonded in a 3-coordinate geometry to three O2- atoms. There is two shorter (1.91 Å) and one longer (1.92 Å) Te–O bond length. There are three inequivalent O2- sites. In the first O2- site, O2- is bonded in a distorted bent 120 degrees geometry to one Zn2+ and one Te4+ atom. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Zn2+ and one Te4+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to two equivalent Zn2+ and one Te4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Cu2Te3O8 by Materials Project

Cu2Te3O8 is Antimony trioxide-derived structured and crystallizes in the monoclinic C2/c space group. The structure is three-dimensional. Cu2+ is bonded to five O2- atoms to form distorted corner-sharing CuO5 trigonal bipyramids. There are a spread of Cu–O bond distances ranging from 1.93–2.19 Å. There are two inequivalent Te4+ sites. In the first Te4+ site, Te4+ is bonded in a see-saw-like geometry to four O2- atoms. There are two shorter (1.91 Å) and two longer (2.12 Å) Te–O bond lengths. In the second Te4+ site, Te4+ is bonded in a 4-coordinate geometry to four O2- atoms. There are a spread of Te–O bond distances ranging from 1.91–2.22 Å. There are four inequivalent O2- sites. In the first O2- site, O2- is bonded in a 3-coordinate geometry to one Cu2+ and two equivalent Te4+ atoms. In the second O2- site, O2- is bonded in a trigonal planar geometry to two equivalent Cu2+ and one Te4+ atom. In the third O2- site, O2- is bonded in a distorted trigonal planar geometry to one Cu2+ and two Te4+ atoms. In the fourth O2- site, O2- is bonded in a bent 120 degrees geometry to one Cu2+ and one Te4+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Ba2ScSbO6 by Materials Project

Sc(BaO3)2Sb is alpha Rhenium trioxide-derived structured and crystallizes in the cubic Fm-3m space group. The structure is three-dimensional and consists of four antimony molecules, four scandium molecules, and one BaO3 framework. In the BaO3 framework, Ba2+ is bonded to six equivalent O2- atoms to form corner-sharing BaO6 octahedra. The corner-sharing octahedral tilt angles are 0°. All Ba–O bond lengths are 2.36 Å. O2- is bonded in a linear geometry to two equivalent Ba2+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Sb2O3 by Materials Project

Sb2O3 is Antimony trioxide structured and crystallizes in the orthorhombic Pccn space group. The structure is three-dimensional. Sb3+ is bonded in a 5-coordinate geometry to five O2- atoms. There are a spread of Sb–O bond distances ranging from 2.02–2.63 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to four equivalent Sb3+ atoms. In the second O2- site, O2- is bonded in a 3-coordinate geometry to three equivalent Sb3+ atoms.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on SbCl3 by Materials Project

SbCl3 is Cementite structured and crystallizes in the orthorhombic Pnma space group. The structure is zero-dimensional and consists of four antimony trichloride molecules. Sb3+ is bonded in a distorted T-shaped geometry to three Cl1- atoms. There are one shorter (2.37 Å) and two longer (2.41 Å) Sb–Cl bond lengths. There are two inequivalent Cl1- sites. In the first Cl1- site, Cl1- is bonded in a single-bond geometry to one Sb3+ atom. In the second Cl1- site, Cl1- is bonded in a single-bond geometry to one Sb3+ atom.

36 MATERIALS SCIENCE↗
DOE OSTI2020

Materials Data on Bi2O3 by Materials Project

Bi2O3 is Antimony trioxide-like structured and crystallizes in the tetragonal P-42_1c space group. The structure is three-dimensional. Bi3+ is bonded to five O2- atoms to form a mixture of distorted corner and edge-sharing BiO5 square pyramids. There are a spread of Bi–O bond distances ranging from 2.16–2.67 Å. There are two inequivalent O2- sites. In the first O2- site, O2- is bonded in a 2-coordinate geometry to four equivalent Bi3+ atoms. In the second O2- site, O2- is bonded in a distorted trigonal planar geometry to three equivalent Bi3+ atoms.

36 MATERIALS SCIENCE↗