Tao Deng

Current neuromorphic vision sensors still struggle to accurately emulate the complex and dynamic photoresponse behaviors of the biological retina, limiting their capability to replicate realistic visual perception characteristics. The integration of two-dimensional (2D) materials with self-rolled-up three-dimensional (3D) microtube architectures has emerged as an effective strategy for constructing neuromorphic vision sensors. Herein, we have systematically demonstrated the functional evolution from a planar WS2 photodetector to a 3D microtube WS2/graphene heterojunction optoelectronic synapse capable of emulating the photoresponse dynamics of the retina. Upon integration of a van der Waals (vdW) heterojunction with graphene and in situ self-rolling into a 3D microtube, the device achieves a pivotal functional evolution: the microtube cavity enhances the light-trapping efficiency, while the curvature-induced strain further modulates the energy band and defect states of materials, triggering the hyperpolarization behavior analogous to that of biological photoreceptors and ON-bipolar cells under optical stimulation. The 3D microtube WS2/graphene heterojunction device delivers a biomimetic composite photoresponse, consisting of an initial current dip corresponding to photoreceptors hyperpolarization, a subsequent current rise mimicking the activation of ON-bipolar cells, a fast decay with undershoot reflecting ON-bipolar cells hyperpolarization, and a prolonged slow recovery process analogous to dark adaptation of rod cells. This work mitigates partial functional mismatches between artificial optoelectronic devices and biological retinal cells and provides a viable route to fabricate neuromorphic vision sensors emulating biological photoresponse characteristics.

High-performance broadband photodetector arrays are pivotal for sensing, imaging and optical communication technologies, yet scalable materials that simultaneously offer broadband photoresponse coverage, fast response speed and uniform device performance remain elusive. Here, we present a 3 × 5 photodetector array based on few-layer MoTe ₂ grown via chemical vapor deposition method. The MoTe ₂ photodetector exhibits a stable photoresponse ranging from ultraviolet to near-infrared regions. The device features a responsivity ( R ) of 3.82 mA W ⁻¹ , an external quantum efficiency of 1.17% and a detectivity ( D *) of 1.62 × 10 ⁷ Jones under 405 nm illumination (5.04 mW cm ² ) at V _ds = 2 V and V _gs = 0 V. The response time and recovery time remain on the millisecond scale throughout the entire photoresponse coverage. This work provides a feasible route toward the construction of high-performance broadband photodetector arrays using single material alone.

Temperature sensors play a vital role in industrial automation, environmental surveillance, and consumer electronics, where precise thermal monitoring is essential for operational reliability and safety. However, traditional temperature sensors are typically unable to function effectively beyond a temperature range of 200 °C, limiting their practical applications for the detection of high-temperature in extreme environments. Herein, we present a thermal protection method involving the growth of a silicon nitride (Si ₃ N ₄ ) protective layer on graphene surfaces followed by thermal annealing to enhance its thermal stability and durability. Using this technique, a graphene-based high-temperature sensor with excellent performance was successfully fabricated, effectively addressing the issue of graphene’s susceptibility to oxidation at elevated temperatures while preventing contamination by impurities. Segmented annealing could alleviate thermally induced stress accumulation and suppresses passivation cracking/bubbling, enabling stable operation in ambient air up to 1250 °C. Moreover, the graphene-based high-temperature sensor demonstrates a broad temperature measurement range, excellent resistance consistency, and a compact design, making it well-suited for diverse applications. And the proposed thermal protection method offers new insights into the design and fabrication of high-temperature sensors, demonstrating significant potential in applications requiring high-temperature endurance, such as aircraft engines and oil wells.

As conventional silicon scaling approaches fundamental physical limits, two-dimensional semiconductors offer a promising pathway for continued transistor miniaturization. Here we show an ultra-scaled vertical MoS₂ transistor that combines a sub-1 nm gate and a 10 nm channel length, realized through a dual-self-aligned fabrication strategy. In this architecture, the exposed edge of a monolayer graphene at etched sidewalls serves as an atomically thin gate electrode, while the sidewalls also act as self-aligned masks for defining an ultra-short MoS₂ channel through oblique-angle deposition. This co-scaling strategy yields an on-state current density of 23 μA/μm and on/off current ratio exceeding 10⁶. Systematic device simulations further elucidate the electrostatic control, effective gate length, and tunneling-limited scaling behavior of this vertical architecture. Beyond individual transistors, we demonstrate wafer-scale arrays and their integration into logic circuits (inverters, NAND, NOR gates), underscoring the scalability and integration potential of this platform.

Three-dimensional (3D) self-rolled-up microarchitectures present a promising avenue to enhance the performance of low-dimensional material-based optoelectronic devices. However, the high-quality, high-yield, and scalable fabrication of these microarchitectures remain challenging. Herein, we demonstrate a 16 × 21 high-yield (∼98%) photodetector array of 3D ReS₂ self-rolled-up microtubes fabricated via a XeF₂ dry-released process on a silicon on insulator substrate (1.5 cm × 1.5 cm). The 3D configuration enhances optical confinement and light absorption, leading to a photocurrent increase of 2 orders of magnitude compared to its planar counterpart. Furthermore, a mixed-dimensional heterojunction formed by integrating MoS₂ quantum dots (QDs) onto ReS₂ results in more than 3-fold and 2-fold improvements in photocurrent and responsivity (R), respectively. The devices also exhibit fast responses (4 ms/6 ms), along with excellent stability and robustness. The finite element simulation and energy band analysis reveal that the architecture synergistically combines the optical localization of 3D geometry, the efficient charge transport of two-dimensional (2D) material, and the strong absorption and band-structure tunability of zero-dimensional (0D) QDs. This study not only demonstrates the unique advantages of XeF₂ dry release in the fabrication of large-scale and high-yield photodetector arrays based on 3D microtube structures for low-dimensional materials but also provides design inspiration for the development of next-generation photodetectors through optical structure design and multidimensional material integration.

Ultraviolet (UV) radiation is a key environmental trigger for the flare-ups of systemic lupus erythematosus (SLE), making personalized UV monitoring and early warning an urgent unmet clinical need for SLE management. Conventional UV detectors, however, cannot adapt to the cumulative and delayed characteristics of UV-induced damage in SLE patients or the interindividual differences in UV sensitivity and thus fail to provide personalized protection strategies. To enable precise UV damage assessment and proactive early warning for SLE patients, we developed an organic optoelectronic synaptic device through poly(amic acid) (PAA)/HfO₂ heterogeneous interface engineering. Notably, these devices bridge fundamental UV detection with clinical personalization, as their bioinspired integration of "sensing-storage-computation" allows for capturing the complex characteristics of UV damage in SLE. The optimized devices demonstrate outstanding performance, featuring high mobility (27.5 cm²V^-1s^-1), responsivity (5.9 × 10⁵ AW^-1), specific detectivity (4.4 × 10¹⁶ Jones), and excellent cycling stability (>5,000 cycles). Functionally, these devices mimic biological sensitization and threshold-triggered responses to reproduce UV damage accumulation, a function unavailable in conventional devices. Dynamic tuning of the optical response threshold through gate voltage further allows customized configuration of early warning levels. Furthermore, the device can generate timely warnings before UV exposure reaches levels linked to SLE flare-ups, thus enabling effective preventive protection. This work offers a new strategy for personalized UV protection in SLE patients and expands the application scope of neuromorphic devices in autoimmune disease management.

Temperature sensors are extensiv-ely utilized in various fields, including aero engines, consumer electronics, and health monitoring. Conventional temperature sensors are typically limited to measurements below 200 °C, rendering them inadequate for applications requiring temperature monitoring in extreme high-temperature environments. This paper presents a micrometer-scale high temperature resistant temperature sensor based on graphene. The device employs graphene as the sensing layer and incorporates a designed silicon nitride/titanium nitride (Si₃N₄/TiN) composite film as a protective layer. This structure effectively prevents the high temperature oxidation of graphene, thereby extending its operational temperature range. Experimental results demonstrate that a protective layer consisting of a 100 nm TiN layer and a 500 nm Si₃N₄ layer exhibits excellent protective performance. The sensor operates effectively in air across a temperature range of 25 °C to 800 °C, exhibiting a high temperature coefficient of resistance (TCR) of 0.26 %•°C⁻¹, along with long-term stability at room temperature. In summary, this device features a micrometer-scale structure, enables array-based fabrication, and demonstrates a high TCR and high-temperature tolerance up to 800 °C. This work offers new insights for the development of graphene-based high-temperature-resistant temperature sensors and expands their potential for diverse applications.