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Abstract Visual adaptive devices have potential to simplify circuits and algorithms in machine vision systems to adapt and perceive images with varying brightness levels, which is however limited by sluggish adaptation process. Here, the avalanche tuning as feedforward inhibition in bionic two-dimensional (2D) transistor is proposed for fast and high-frequency visual adaptation behavior with microsecond-level accurate perception, the adaptation speed is over 104 times faster than that of human retina and reported bionic sensors. As light intensity changes, the bionic transistor spontaneously switches between avalanche and photoconductive effect, varying responsivity in both magnitude and sign (from 7.6 × 104 to −1 × 103 A/W), thereby achieving ultra-fast scotopic and photopic adaptation process of 108 and 268 μs, respectively. By further combining convolutional neural networks with avalanche-tuned bionic transistor, an adaptative machine vision is achieved with remarkable microsecond-level rapid adaptation capabilities and robust image recognition with over 98% precision in both dim and bright conditions.

Abstract Resistive switching memories have garnered significant attention due to their high‐density integration and rapid in‐memory computing beyond von Neumann's architecture. However, significant challenges are posed in practical applications with respect to their manufacturing process complexity, a leakage current of high resistance state (HRS), and the sneak‐path current problem that limits their scalability. Here, a mild‐temperature thermal oxidation technique for the fabrication of low‐power and ultra‐steep memristor based on Ag/TiOx/SnOx/SnSe2/Au architecture is developed. Benefiting from a self‐assembled oxidation layer and the formation/rupture of oxygen vacancy conductive filaments, the device exhibits an exceptional threshold switching behavior with high switch ratio exceeding 106, low threshold voltage of ≈1 V, long‐term retention of >104 s, an ultra‐small subthreshold swing of 2.5 mV decade−1 and high air‐stability surpassing 4 months. By decreasing temperature, the device undergoes a transition from unipolar volatile to bipolar nonvolatile characteristics, elucidating the role of oxygen vacancies migration on the resistive switching process. Further, the 1T1R structure is established between a memristor and a 2H‐MoTe2 transistor by the van der Waals (vdW) stacking approach, achieving the functionality of selector and multi‐value memory with lower power consumption. This work provides a mild‐thermal oxidation technology for the low‐cost production of high‐performance memristors toward future in‐memory computing applications.

Abstract In recent years, 2D reconfigurable phototransistors (RPTs) have been applied in broadband convolutional processing, retinomorphic hardware devices, and non‐volatile memorizers. However, there has been a lack of investigation into all‐2D Schottky junctions used in RPT with polarity control behavior. Herein, a vertically stacked multilayered WS2/WTe2 Schottky RPT is reported. The semimetal characteristics of 1T’‐WTe2 is designed to form a built‐in electric field of 69 meV across the heterojunction and WS2 exhibits gate‐tunable characteristics. Therefore, reconfigurable rectifying behavior and self‐driven bidirectional photo response can be achieved. The phototransistor possesses a gate‐tunable rectification ratio ranging from 10−2 to 105, and the corresponding logic half‐wave rectifier shows excellent switchable rectifying states. Under 635 nm illumination, the responsivity can be adjusted from −1325 to 430 mA W−1 with reversed signs. Meanwhile, the maximum power conversion efficiency is 2.84%, and the specific detectivity is 1.47 × 1012 Jones. The device shows both negative and positive responsivity with linear gate dependence within a voltage window of 10 V. Impressively, nonvolatile photovoltaic performance can be demonstrated by reversing short‐circuit current and open‐circuit voltage by applying and releasing pulsed gate voltage. Finally, reconfigurable polarization behavior, single‐pixel imaging, and the optical logic circuit are applicable to the heterostructure.

Carrier mobility is one of most important figures of merit for materials that can determine to a large extent the corresponding device performances. So far, extensive efforts have been devoted to the mobility improvement of two-dimensional (2D) materials regarded as promising candidates to complement the conventional semiconductors. Graphene has amazing mobility but suffers from zero bandgap. Subsequently, 2D transition-metal dichalcogenides benefit from their sizable bandgap while the mobility is limited. Recently, the 2D elemental materials such as the representative black phosphorus can combine the high mobility with moderate bandgap; however the air-stability is a challenge. Here, we report air-stable tellurium flakes and wires using the facile and scalable physical vapour deposition (PVD) method. The prototype field-effect transistors were fabricated to exhibit high hole mobility up to 1485 cm2 V−1 s−1 at room temperature and 3500 cm2 V−1 s−1 at low temperature (2 K). This work can attract numerous attentions on this new emerging 2D tellurium and open up a new way for exploring high-performance optoelectronics based on the PVD-grown p-type tellurium.

Hybrids composed of two-dimensional (2D) and zero-dimensional (0D) materials have demonstrated great application potentials in electronics and optoelectronics. The CdSe@Zn1−XCdXS (CSZCS) quantum dots (QDs) possess unique gradient band structure with a continuously increasing energy level along the radial direction from the center to the surface, which is favorable for light-harvesting, photocarrier transfer and promising for photovoltaic and photodetection applications. Here, the gradient alloyed CSZCS QDs, acting as a photosensitive layer, have been first integrated with 2D InSe as a carrier transport layer. The new 2D–0D hybrids exhibit a 300-fold improvement in responsivity compared with that of pristine InSe, which is much more superior to hybrids composed of core–shell CdSe@ZnS QDs/InSe. Thanks to the low dark current and large photo-gain induced by the photo-gating effect, the responsivity and detectivity of the CSZCS QDs/InSe photodetector can reach up to 30.16 A/W and 1.69 × 1012 Jones, respectively. This work provides a new kind of promising QDs with the gradient alloyed structure that can be explored into 2D–0D hybrids for further development of high-performance photodetectors.

Providing large-scale iodide capped semi-conductive PbS nanocrystals inks preparation for high-throughput manufacturing remains a challenge. Here, the authors propose a direct one step and scalable synthesis method enabling cost reduction and promoting its commercial viability for solar cells.

Magnetic multilayer with large perpendicular magnetic anisotropy (PMA) has attracted sustained interest owing to its importance to fundamental physics and applications. In this work, the high quality of Pt/Co/Pt heterostructures with large PMA was successfully achieved to exhibit a large anomalous Hall effect (AHE) with squared Hall loops. By calculating the proportional relationship between the longitudinal resistivity (ρxx) and the abnormal Hall coefficient (Rs), it is confirmed that the basic mechanism of AHE comes from the external skew scattering (SS) and side jump (SJ), while SS contribution, related to asymmetric scattering from impurities, is dominant in the AHE. Furthermore, the obvious magneto-optical Kerr effect (MOKE) was also observed using the polar MOKE microscopy. The obviously circular magnetic domain can form and propagate in response to the applied out-of-plane magnetic field, resulting in the magnetization reversal of the entire film. This work offers important information in terms of both AHE and MOKE in the ultrathin ferromagnetic films with perpendicular anisotropy, establishing the application foundation for the nonvolatile memories and spintronics.

Photodetectors based on 2D transition metal dichalcogenides exhibit ever increasingly competitive performance, yet not superior to that of alternative technologies. Here, the authors devise a MoS2-based phototransistor with an out-of-plane junction, yielding a record detectivity combined with broadband response.