SinoGreenTech Academic Portal
JK
Verified CAS / Academic Author5 Decoded Studies

Prof. JIA Kun

School of Materials Science and Engineering, Taiyuan University of Science and Technology, Taiyuan 030024, China

Research Publications & English Decoded Briefs

Showing 5 publications
SCIENCE CHINA Materials2026DOI: 10.1007/s40843-026-4391-5

Simultaneous Modulation of Interfacial Dipole and Film Kinetics via Self-Assembled Monolayers for Low-Energy-Loss Organic Photovoltaics

Self-assembled monolayers (SAMs) enable precise tuning of the ITO/active layer interfacial dipole, yet their impact on the crystallization kinetics of the overlying active layer remains poorly understood, limiting their potential in high-efficiency organic solar cells. This study introduces THPC, a self-assembling material with an extended carbazole core and heteroatom substitution, as a hole transport layer (HTL). Unlike the hydrophilic PEDOT:PSS, THPC exhibits low surface energy, providing a favorable template that extends the film formation kinetics of the PM6:L8-BO-X blend by nearly 1.4 times, mitigating the explosive nucleation prevalent in PM6-based active layers. This promotes a highly ordered fibrous morphology and enhances vertical phase separation. The deep work function of THPC (5.32 eV) increases the built-in potential, reduces interfacial trap density, and facilitates charge extraction. Consequently, non-radiative recombination loss decreases from 0.243 eV to 0.227 eV, and the open-circuit voltage rises from 0.866 V to 0.883 V, yielding a power conversion efficiency (PCE) of 20.19%, outperforming the PEDOT:PSS control (18.67%). This finding is confirmed across multiple Y-series acceptors, all approaching 20% PCE. Notably, the D18:L8-BO system achieves a PCE of 20.55%, demonstrating broad applicability.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-3761-7

Ruthenium-Based Electrocatalysts for Electrochemical Water Splitting: A Review of Fundamentals, Synthesis, and Enhancement Strategies

Ruthenium-based materials, including metallic Ru and RuO2, are promising electrocatalysts for electrochemical water splitting (EWS) due to their high activity for both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER). However, their practical application is hindered by the relatively strong adsorption of reaction intermediates on Ru surfaces and the oxidative dissolution of RuO2 under operating conditions. This review provides a comprehensive overview of recent progress and challenges in Ru-based electrocatalysts for EWS. We first summarize the fundamentals of EWS, including reaction mechanisms and activity descriptors. Then, we detail typical synthesis methods such as hydrothermal/solvothermal syntheses, organic ligand-assisted syntheses, pyrolysis, acid etching, cation exchange, and molten salt-assisted syntheses. Subsequently, we focus on enhancement strategies, including alloying, doping, structure design, interface engineering, single-atom catalyst design, high-entropy alloy design, phase engineering, and defect engineering, with typical examples illustrating structure-property correlations. Finally, we address remaining challenges and future prospects for the development of efficient and durable Ru-based electrocatalysts for sustainable hydrogen production.

Journal of Fuel Chemistry and Technology2026DOI: 10.3724/2097-213X.2025.JFCT.0021

Fabrication and Microwave Absorption Performance of FexOy/TiO2/C Composites Derived from Red Mud

Red mud, an industrial solid waste from alumina production, poses severe environmental challenges. This study presents a resource-efficient strategy to convert red mud into high-performance microwave absorbing materials. FexOy/TiO2/C composites were synthesized via a sol-gel method using starch as carbon source, followed by carbothermal reduction. The phase composition and microstructure were optimized by adjusting calcination temperature and raw material ratio. The optimal sample, RmCT-5.4-700, exhibited a minimum reflection loss (RLmin) of -30.2 dB at 14.0 GHz with an effective absorption bandwidth (EAB) of 5.3 GHz at a coating thickness of 2.0 mm. The superior absorption performance is attributed to the synergistic effects of dielectric components (TiO2, graphitized carbon) and magnetic components (Fe3O4/Fe). Carbothermal reduction introduces defects that induce dipole polarization, while the conductive network formed by graphitized carbon and Fe3O4/Fe particles enhances conductive loss. Heterogeneous interfaces between Fe3O4, Fe, TiO2, and the red mud matrix promote interfacial polarization. The magnetic loss of Fe3O4/Fe improves impedance matching, facilitating electromagnetic wave penetration and absorption. This work not only provides a novel route for red mud valorization but also contributes to the high-value utilization of solid wastes.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-3779-1

Comprehensive Mechanical Properties of Oxide Ceramics Measured by Nanoindentation: RE3TaO7 (RE=La, Sm, Eu, Gd, Dy, Lu) as a Study Case

Comprehensive mechanical properties, including hardness (H), elastic modulus (E), fracture toughness (KC), and wear resistance, are essential for oxide ceramics used in demanding environments. This work employs nanoindentation to evaluate these properties for RE3TaO7 (RE=La, Sm, Eu, Gd, Dy, Lu) and identifies the optimal calculation method for KC in brittle oxide ceramics. The ratio of indentation crack length to half-diagonal (l/α) is a key parameter: Eq. (3) is suitable when l/α < 1, while Eq. (4) applies when l/α > 1. The indentation energy method is invalid for brittle ceramics due to crack formation at high loads. RE3TaO7 oxides exhibit H of 5.8–14.9 GPa, E of 127.5–247.8 GPa, and KC of 1.0–2.0 MPa·m1/2, surpassing RE2Zr2O7 (KC 1.0–1.5 MPa·m1/2). Wear resistance, indicated by MDP, ranges from 0.55 to 0.67, outperforming RE2Zr2O7. The superior fracture toughness is attributed to weberite structure with crack deflection and tortuous propagation, contrasted with pyrochlore's straight cracks. These findings provide accurate nanoindentation-based methods for assessing mechanical properties of brittle oxide ceramics, facilitating material discovery and optimization for thermal barrier coatings and other high-temperature applications.

SCIENCE CHINA Materials2026DOI: 10.1007/s40843-025-4009-0

Full-color high brightness Micro-LED displays with high bonding yield realized via photosensitive conductive polymeric bumps

Micro light-emitting diode (Micro-LED) display technology is a promising next-generation display technology due to its high brightness, high contrast, low power consumption, long life, and fast response. However, aggressive downscaling of Micro-LEDs to a few microns makes lift-off fabrication of metal bumps for soldered joints between Micro-LEDs and driver substrates increasingly difficult, challenging high-yield bump arrays under high-density conditions. This study innovatively replaces conventional metal bumps with a photosensitive conductive polymer (PCP), enabling fabrication of polymeric micro-bump arrays via well-established photolithography, bypassing complex lift-off processes and reducing short-circuit risk. Isopropyl alcohol regulates developer wettability for optimal development, yielding bump arrays with bump size 20 μm × 12 μm and height (1.9288 ± 0.0213) μm on thin-film transistor (TFT) drivers with yield over 99.99%. The issue of low bonding yield from polydimethylsiloxane (PDMS) thermal expansion was resolved by adjusting chip spacing on the temporary substrate, achieving bonding yield exceeding 99.8%. A 0.99-inch full-color Micro-LED display with density 114 pixels per inch (PPI) and brightness 5537 cd/m² was fabricated. High-yield bump arrays, Micro-LED arrays, and high bonding yield are highly reproducible, promoting development of Micro-LED displays and related fields.