arXiv subjects

Sang-Hyun Chin

Publications and source records attributed to Sang-Hyun Chin.

5 recordsLinked to original sources

arXiv2026

Light-Emitting Diodes with Micrometer-Thick Perovskite Charge Transport Layers

Over the past few decades, thin-film optoelectronic devices have shown significant advancements. Light-emitting diodes (LEDs) based on organic materials, polymers, quantum dots, as well as metal halide perovskites have achieved remarkable efficiencies and long lifetimes, making them ideal for applications in full-color displays and solid-state lighting. These devices typically feature a layered structure, with the light-emitting layer positioned between charge transport layers and two electrodes. This perspective reviews recent progress in LEDs utilizing perovskite charge transport layers and suggests potential pathways for further development in this field.

cond-mat.mtrl-sci↗

arXiv2025

Amplified Photocurrent in Heterojunctions comprising Nano-rippled Zinc Oxide and Perovskite-inspired Cs3Cu2I5

Molecular zero-dimensional (0D) halide perovskite-inspired cesium copper iodide (Cs3Cu2I5) is a highly promising candidate for optoelectronic applications due to their low toxicity, high stability, and intense blue emission. However, their intrinsically poor electrical conductivity, stemming from isolated conductive copper iodide tetrahedra by cesium atoms, severely limits charge transport which poses a critical challenge for optoelectronic applications. In this study, we propose a novel strategy to overcome this limitation by utilizing precisely optimized zinc oxide nanoripple structures within a lateral Cs3Cu2I5 photodetector (PD) architecture featuring interdigitated electrodes (IDEs). The ZnO nanoripple was systematically tuned to improve the percolation paths, providing efficient routes for photogenerated carriers to migrate to the IDEs. Consequently, the optimized heterojunctions comprising Cs3Cu2I5 and ZnO exhibited superior photocurrent compared to the pristine Cs3Cu2I5 counterparts. This nanostructure-mediated charge transport engineering strategy for lateral structured PDs offers a new pathway for utilizing low-conductivity 0D materials for conventional optoelectronics, next-generation Internet of Things sensor networks, and plausibly biosensing applications.

cond-mat.mtrl-sci↗

arXiv2025

Rapid Vapor-Assisted Solution Process of Metal-Organic Chalcogenides for High-Performance Light-Emitting Diodes

Metal-organic chalcogenides (MOCs), robust crystalline assemblies composed of coinage metals, chalcogens and organic ligands, are typically synthesized via prolonged, high temperature tarnishing of vacuum-deposited metal films with organochalcogen precursors. The prolonged exposure to high temperatures and the necessity for direct vacuum deposition of silver can induce damage to the underlying films, posing significant challenges to the fabrication of optoelectronic devices, despite their cost-effectiveness and chemical robustness. This study introduces vapor-assisted solution processing, a novel chemical vapor deposition method, enabling remarkably rapid fabrication of luminescent MOC films. Furthermore, the first MOC-based light-emitting diodes (MOCLEDs) are realized, achieving an external quantum efficiency (EQE) approaching 0.1% and electroluminescence peaking at 633 nm. These results highlight the potential of MOCs as next-generation emitters for displays and solid-state lighting. This work offers a promising fabrication strategy and insights for advancing MOCLEDs and expanding their optoelectronic potential.

cond-mat.mtrl-sci↗

arXiv2021

Binding Sites, Vibrations and Spin-Lattice Relaxation Times in Europium(II)-based Metallofullerene Spin Qubits

To design molecular spin qubits with enhanced quantum coherence, a control of the coupling between the local vibrations and the spin states is crucial, which could be realized in principle by engineering molecular structures via coordination chemistry. To this end, understanding the underlying structural factors that govern the spin relaxation is a central topic. Here, we report the investigation of the spin dynamics in a series of chemically-designed europium(II)-based endohedral metallofullerenes (EMFs). By introducing a unique structural difference, i.e. metal-cage binding site, while keeping other molecular parameters constant between different complexes, these manifest the key role of the three low energy metal-based vibrations in mediating the spin-lattice relaxation times (T1). The temperature dependence of T1 can thus be normalized by the frequencies of these low energy vibrations to show an unprecedentedly universal behavior for EMFs in frozen CS2 solution. Our theoretical analysis indicates that this structural difference determines not only the vibrational rigidity but also spin-vibration coupling in these EMF-based qubit candidates.

physics.chem-ph↗

arXiv2018

Polar Solvent Vapour Induced Photo-Physical Properties on the Solid-State Organometallic Halide Perovskite Nanocrystals

The optoelectric applications, light emitters and photovoltaics, with organometallic halide perovskite materials have been decided by dynamics of charge carriers in grains on the polycrystalline thin films. Especially, polar solvent vapour recrystallizes perovskites and changes their grain sizes. In this paper, various polar solvents were evaluated with density functional theory calculation. And a stociometric treatment with these solvents which enhanced photoluminescence intensity was established. The properties of solvents which caused dramatic photoluminescence enhancement and quantum confinement effect were discussed.

physics.app-ph↗