Orientation-engineered epitaxial BiVO ₄ thin films for efficient photoelectrochemical glycerol valorization

Materials Horizons · 2026-01-01 · 1 citations

0) facet originates primarily from improved bulk charge separation and transport rather than surface catalytic effects. This work establishes crystallographic orientation control as an effective design strategy for developing energy-efficient oxide photoanodes for solar-driven glycerol oxidation beyond conventional water splitting.

Bias-tunable temperature coefficient amplification beyond material limits in a single transistor

Nature Sensors · 2026-04-17

Bias-tunable temperature coefficient amplification beyond material limits in a single transistor

Figshare · 2026-04-18

All of these files are in excel form.

Emerging conduction pathways in semiconducting bismuth-antimony alloys

Journal of Physics Condensed Matter · 2026-03-31

Abstract As strong topological insulators, Bi <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi/> <mml:mrow> <mml:mn>1</mml:mn> <mml:mo>−</mml:mo> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> Sb x alloys with <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mrow> <mml:mo>∼</mml:mo> </mml:mrow> <mml:mn>0.07</mml:mn> <mml:mo>&lt;</mml:mo> <mml:mi>x</mml:mi> <mml:mo>&lt;</mml:mo> <mml:mn>0.22</mml:mn> </mml:mrow> </mml:math> are predicted to host topologically protected conduction pathways along extended defects, such as dislocations. Due to the presence of bulk conduction, these fascinating topological features have been obscured to date. We examine carrier transport and electronic states in high-purity single-crystals of Bi <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:msub> <mml:mi/> <mml:mrow> <mml:mn>1</mml:mn> <mml:mo>−</mml:mo> <mml:mi>x</mml:mi> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> Sb x alloys with 11 at% Sb. Using high magnetic fields, we suppress bulk conduction, enabling the identification of the residual conductivity associated with extended defects. A two-band analysis of magnetotransport measurements in combination with angle-resolved photoemission spectroscopy, reveals a bandgap <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" overflow="scroll"> <mml:mrow> <mml:mtext>⩾</mml:mtext> </mml:mrow> </mml:math> 40 meV, larger than Arrhenius analyses of temperature-dependent resistivities. With mobility as high as 750 000 cm 2 V −1 s −1 , Bi–Sb alloys are promising candidates for topological electronics and related applications.

Bias-tunable temperature coefficient amplification beyond material limits in a single transistor

Figshare · 2026-04-18

All of these files are in excel form.

Advances in wide-bandgap III-V solar cells

Applied Physics Reviews · 2025-07-17 · 3 citations

III-V multi-junction solar cells have yielded the highest solar cell efficiencies for nearly three decades and recently achieved record efficiencies approaching 40% under standard conditions and 50% under concentrated sunlight. Such high efficiencies are currently only possible using four or more junctions to partition the broad solar spectrum into bins where each subcell efficiently collects a narrow range of photon energies. High-efficiency, wide-bandgap (1.7–2.2 eV) absorbers play a crucial role in multi-junction solar cells by efficiently converting visible photons into electrons and delivering them at high voltage. Since all subcells are interconnected in series, the widest bandgap junction produces both the highest voltage and highest power in the stack. Wide-bandgap absorbers also present the greatest materials challenges in the stack, including high aluminum content, lattice mismatch, lack of heterojunction barriers, and the sensitivity of phosphides to defects such as vacancies and oxygen. We review the history, current status, and opportunities for wide-bandgap III-V solar cells, ranging from ∼1.7 eV for the top subcell of III-V/Si hybrid tandems to &amp;gt;2.2 eV for the top subcell of a 6+ junction stack. Future directions and recommendations to overcome remaining materials and device challenges will be discussed.

Evaluating the Potential of Polycrystalline Al_0.25Ga_0.75P and Al_0.9Ga_0.1As as Hole Contacts in Silicon Heterojunction Solar Cells

IEEE Journal of Photovoltaics · 2025-02-06

The parasitic absorption of visible light in amorphous silicon layers can result in a short-circuit current density (<italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">J</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sc</sub>) loss of up to 2 mA/cm<sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sup> for silicon heterojunction solar cells. To mitigate this issue, we explore the potential for polycrystalline Al<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.25</sub>Ga<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.75</sub>P and Al<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.9</sub>Ga<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.1</sub>As, both <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">nonepitaxially</i> deposited at 250 °C, to enable high <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">J</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sc</sub> while serving as alternative hole contacts to p-type amorphous silicon [a-Si:H(p)]. Using a suite of device characterization methods, we investigate how the passivation changes with the deposition of these III–V materials and their degree of hole selectivity. We identify that both Al<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.25</sub>Ga<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.75</sub>P and Al<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.9</sub>Ga<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.1</sub>As can still enable high implied open-circuit voltages >720 mV; however, they are not hole selective enough to enable high open-circuit voltage and fill factor. Ultimately, the best performing solar cells are limited to 9.6% and 10.8% efficiency with a nominal 5 nm of Al<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.25</sub>Ga<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.75</sub>P and a measured 13 nm of Al<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.9</sub>Ga<sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">0.1</sub>As, respectively. However, both cells demonstrate higher <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">J</i><sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">sc</sub> than a reference cell with a-Si:H(p) that has a similar nominal thickness.

GaAsP on Si Single-Junction Solar Cells with Enhanced Short-Circuit Current Density Enabled by Distributed Bragg Reflectors

2025-06-08

We present the first GaAs0.77P0.23 single junction solar cells on Si with an Al0.20Ga0.80As0.77P0.23/Al0.80Ga0.20As0.77P0.23 distributed Bragg reflector (DBR) to increase long-wavelength quantum efficiency. The 20-period (2.3 μm) DBR achieves reflectance >95.0% in air and a bandwidth of ~55 nm. Thinning the cell' graded buffer and absorber enables DBR incorporation without cracking from thermal expansion mismatch while maintaining a threading dislocation density of 7-8×106 cm-2. The DBR enhances quantum efficiency near the GaAsP cell band edge, increasing the JSC by 1.42 mA/cm2 and efficiency by 1.46% (absolute) over the baseline cell. Overall, we attain an efficiency of 15.06% with a 750 nm thick absorber, showing promise for current-matched GaAsP/Si tandems with improved performance.

A Study on Trans-Identity Storytelling Based on RP Servers: Focusing on the Case of Bongnudo

Asia Cultural Creativity Institute · 2025-12-30

This study analyzes how identity is constructed and transformed within the real-time interactive narrative environment of the GTA V–based Rroleplay (RP) server “Bongnudo,” using the theoretical framework of trans-identity. While existing discussions of trans-identity have largely focused on text-centered narratives such as film and television, RP servers constitute a narrative field characterized by improvisation, relational performance, multiple perspectives, and platform-dependent structures. In this environment, identity is not predetermined by a fixed character “setting,” but is continuously reorganized through a player’s choices, interactions with others, audience reception, and the unpredictability of emergent events. To clarify these structural conditions, this study first identifies the narrative and platform-specific features of RP servers, and then applies Lim Daegeun’s four types of trans-identity—reversal, displacement, traversal, and transcendence—to the identity transformation structures that emerge within them. Analysis of the characters Rachel (Mareflos) and Gangdulgi (Kang So-yeon) demonstrates that identity transformation in RP servers functions not as a scripted character shift but as a dynamic “event of identity,” mediated through performance, relationality, and situational contingency. By extending trans-identity theory to the domain of real-time interactive narratives, this study argues that RP servers operate as novel devices for generating identity in contemporary media environments. The findings provide a theoretical foundation for research on RP servers and offer a new analytical framework for understanding identity formation in real-time digital content.

Photopumped Buried Dielectric Photonic-Crystal Surface-Emitting Lasers

IEEE photonics journal · 2025-04-15 · 1 citations

We propose and demonstrate a photonic-crystal surface-emitting laser (PCSEL) design utilizing sub-micron buried dielectric features as the low-index component of the photonic crystal. PCSELs are semiconductor lasers with exceptional beam characteristics, including high brightness and narrow, round spot sizes, making them attractive sources for applications such as LiDAR, optical communications, material processing, and directed energy. However, mass transport deformation in InP-based materials can challenge the integrity and uniformity of conventional encapsulated air void photonic crystals. To overcome this, we fabricate buried dielectric PCSELs designed to preserve the photonic crystal structure during regrowth and enhance reliability under high-power and high-current-density operation. We report the first lasing from a photopumped buried dielectric PCSEL at room temperature with emission at 1.5 <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$\mu$</tex-math></inline-formula>m, utilizing fully encapsulated dielectric features fabricated by lateral epitaxial overgrowth via molecular-beam epitaxy (MBE).