Science Highlights

Recently, addressing the inherent timescale mismatch challenge between fast and slow responses in optoelectronic sensors, a collaborative team from Suzhou Institute of Nano-Tech and Nano-Bionics (SINANO), Chinese Academy of Sciences (Yukun ZHAO, Shulong LU, Min JIANG), Fudan University (Lifeng BIAN), and Suzhou University of Science and Technology (Jianya ZHANG) has proposed an innovative monolithic integration scheme. By combining surface defect introduction and local contact interface design with a gallium nitride (GaN) nanowire lift-off technique that eliminates the interference from the underlying silicon substrate, the team integrates fast and slow responses into a single device. This results in a transparent bifunctional device capable of self-driven detection and neural synaptic integration, with omnidirectional (360°) detection capability. As a photodetector, the device demonstrates the millisecond-level response speeds, while it exhibits the second- to minute-level relaxation time as an artificial synapse, achieving an over 1000-fold contrast in response dynamics. The device has been validated in the intelligent perception systems for humanoid robots successfully, advancing the development of multifunctional monolithic optoelectronic devices and providing a solid foundation for further research in related fields.

 

The work entitled "A dual-mode transparent device for 360° quasi-omnidirectional self-driven photodetection and efficient ultralow-power neuromorphic computing" was published in Light: Science & Applications.

Ultrawide bandgap semiconductor optoelectronic synapses can perform high-parallel computing with low false alarm rate, making them ideal for building deep-ultraviolet (DUV) neuromorphic visual system (NVS). Scientists in China developed a breakthrough DUV optoelectronic synapse using Ga₂O₃-based cascade heterojunctions. The device mimics biological vision with 4,096 conductance states and ultrahigh linearity, enabling high-accuracy fingerprint recognition and fault-tolerant logic operations. This innovation paves the way for energy-efficient neuromorphic vision systems in military, environmental monitoring, and secure communications.

Scientists in Korea developed a photopatterning approach for emissive layer (EML) patterns using prepatterned photoresist based on a molecular crosslinking strategy. This approach enables ultra-high resolution up to 3000 ppi—fulfilling AR display requirements—without direct exposure of EML to etchants or UV irradiation, unlike conventional photolithography. The simple method offers a promising route for high-resolution OLEDs for VR/AR applications

Overcoming fundamental power limitations in single-frequency fiber lasers—long constrained by stimulated Brillouin scattering effect (SBS) and transverse mode instability effect (TMI)—Chinese researchers combined optic-acoustic-thermodynamic multi-physics comprehensive analysis and innovatively proposed the insight of using a regionally refractive index design to suppress SBS and TMI. Their ‘bat-type’ refractive-index fiber achieved the first kilowatt breakthrough in single-frequency fiber lasers internationally, which could provide a novel laser source for next-generation advanced detection and sensing systems.

This work reports the design of an efficient multiband UC system based on Ln³⁺/Yb³⁺-doped core-shell upconversion nanoparticles (Ln/Yb-UCNPs, Ln³⁺=Ho³⁺, Er³⁺, Tm³⁺). In the design, Ln³⁺ ions are incorporated into distinct layers of Ln/Yb-UCNPs to function as near-infrared (NIR) absorbers across different spectral ranges. This design achieves broad multiband absorption withtin the 1100 to 2200 nm range, with an aggregated bandwidth of approximately 500 nm. It can effectively extend the photovoltaic performance of silicon solar cells.

Miniaturized fiber-optic magnetic field sensors have attracted intensive interests due to the superiorities of anti-electromagnetic interference and compactness. Scientist in China developed an ultracompact multicore fiber (MCF) tip probes for magnetic field and temperature discriminative sensing. The size of the whole sensing probes does not exceed the inherent outer diameter of the MCF, which means a significant reduction in the size of multi-parameter sensor. The technique will open new avenues towards the realization of an all-fiber miniaturized multi-parameter sensor.

Multicore fibres, one of the candidates for next-generation high-capacity communication carriers, have a complex internal structure that limits their manufacturing monitoring, fibre splicing, and micro-nano processing to some extent. To solve this problem, Chinese scientists have discovered a different way of imaging that can help people see the internal structure of optical fibres better and obtain higher measurement precision. This technology will open a new, structured light-based imaging pathway for future specialty fibre measurements.

Optical skyrmions are a novel family of topological quasiparticles of light with great potential in high-density informatics, but always require complex generation systems yet producing limited topologies. An internationally collaborated group demonstrated an extended family of quasiparticles beyond normal skyrmions generated from needle-like compact photonic gradient-index media, such as multiskyrmions and multimerons with increasingly complex topologies. The compact generator lends to integrated and programmable solutions of complex topologies for revolutionizing topological informatics and logic devices.