SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-026-4351-8
Breaking intrinsic structural symmetry is a fundamental prerequisite for pronounced nonlinear optical responses. Low-symmetry semiconductors with inherent anisotropy enable self-powered optoelectronic conversion and polarization-sensitive functionalities. This work reports the synthesis of low-dimensional van der Waals chain TeSe2 crystals with intrinsic inversion and C3 symmetry breaking. Angle-resolved polarized Raman spectroscopy and second-harmonic generation measurements confirm crystalline anisotropy and nonlinear optical performance. Electrical transport studies reveal p-type conduction with a room-temperature field-effect mobility of 122 cm2 V-1 s-1. The TeSe2 photodetector achieves self-powered detection and linearly polarized light detection across 405–1064 nm, with a photoresponsivity of 77.3 mA/W at 532 nm. The linear photogalvanic effect response is effectively modulated by gate voltage. Density functional theory calculations attribute p-type doping to Te and Se vacancies, while the nonlinear optical origin is linked to strong Berry curvature. Applications in polarization encoding communication and polarization imaging are demonstrated, indicating potential for low-energy-consuming, highly sensitive, on-chip integrated linear polarized photodetectors.
SCIENCE CHINA Materials•2026•DOI: 10.1007/s40843-025-4061-5
The dynamic modulation of magnetic properties by external stimuli represents a paradigm shift in materials science, enabling non-contact, reversible control of spin states for applications in optical switching, sensing, and low-power spintronics. Prussian blue analogues (PBAs) are versatile platforms for photo-responsive magnetism, yet their photomagnetic response is highly sensitive to transition metal selection, alkali ions, vacancies, and water content, complicating targeted synthesis. Here, we introduce a generalizable strategy by incorporating the photo-responsive organic cation methyl viologen (MV2+) into PBA frameworks, yielding hybrids MVPB, MVPB-Co, and MVPB-Ni. Upon Xe lamp irradiation, MV2+ undergoes reduction to the radical cation MV+•, which acts as a spin carrier coupling to the magnetic moments of the metal ions. This mechanism decouples the photomagnetic response from the inorganic lattice, overcoming stoichiometric limitations. Irradiation leads to a substantial enhancement of magnetization, followed by partial relaxation under prolonged exposure, attributed to the generation and accumulation of MV+• radicals. These radicals function as dynamic magnetic modifiers, distinct from conventional light-induced charge transfer in PB frameworks. The approach is applicable across diverse cyanide-bridged metal pairs, irrespective of alkaline cations, vacancies, or water content, establishing a robust route for designing light-responsive magnetic materials.