Nanostructured ZnO with its unique properties could provide a suitable microenvironment for immobilization of enzymes while retaining their biological activity, and thus lead to an expanded use of this nanomaterial for the construction of electrochemical biosensors with enhanced analytical performance. ZnO-based enzyme electrochemical biosensors are summarized in several tables for an easy overview according to the target biosensing analyte (glucose, hydrogen peroxide, phenol and cholesterol), respectively. Moreover, recent developments in enzyme electrochemical biosensors based on ZnO nanomaterials are reviewed with an emphasis on the fabrications and features of ZnO, approaches for biosensor construction (e.g., modified electrodes and enzyme immobilization) and biosensor performances.

We report the fabrication and electrical performance of nanoscale vacuum channel transistor (NVCT) based on graphene. Ninety-nanometer-width vacuum nano-channel could be precisely fabricated with standard electron beam lithography process. The optimization and treatment of surface damage and adhesive residue on graphene are carried out by ultrasonic cleaning and thermal annealing. Additionally, in situ electric characteristics are directly performed inside a vacuum chamber of scanning electron microscope (SEM) with the nanomanipulator. By modulating the gate voltage, the NVCT could be switched from off-state to on-state, exhibiting an on/off current ratio up to 102 with low working voltages (< 20 V) and leakage current (< 0.5 nA). Furthermore, the nanoscale vacuum channel could enable to scale down the size of vacuum devices with high integration, making NVCT a promising candidate for high speed applications.

Recent discoveries in the field of graphene‐based heterostructures have led to the demonstration of high‐performance photodetectors. However, the studies to date have been largely limited to the heterojunction with a Schottky barrier, restricted by an inevitable compromise between photoresponsivity and photodetectivity. Here, a new class of graphene‐based tunneling photodetectors is introduced by inserting the Al ₂ O ₃ tunneling layer between silicon and graphene. The photocarriers can tunnel through the designed insulator layer which simultaneously blocks the dark current, thus maintaining high photodetectivity with desirable photoresponsivity. We further modulate the thickness of the Al ₂ O ₃ layer to explore the tunneling mechanism for the photocarriers, in which a photoresponsivity of 0.75 A/W, a high current ratio of 4.8 × 10 ³ and a photodetectivity of 3.1 × 10 ¹² Jones are obtained at a 13.3‐nm‐thick Al ₂ O ₃ layer. In addition, the fabrication process is compatible with conventional semiconductor processing, providing further flexibility to large‐scale integrated photodetectors with high performance.

Nanoscale vacuum channel transistors (NVCTs) are promising candidates in electronics due to their high frequency, fast response and high reliability, and have attracted considerable attention for structural design and optimization.

Due to its unique structure, discoveries in nanoscale vacuum channel transistors (NVCTs) have demonstrated novel vacuum nanoelectronics. In this paper, the structural parameters of planar-type NVCTs were simulated, which illustrated the influence of emitter tip morphology on emission performance. Based on simulations, we successfully fabricated back-gate and side-gate NVCTs, respectively. Furthermore, the electric properties of NVCTs were investigated, showing the potential to realize the high integration of vacuum transistors.

Zero-dimension (0-D) lead halide perovskite nanocrystals (NCs) have attracted a sight of interest in the field of optoelectronic devices due to their outstanding properties, such as high photoluminescence quantum yield (PLQY) and size- and composition-controlled tunable emission wavelengths. However, the toxicity of lead (Pb) element in the lead perovskite NCs is the bottleneck for the commercial application of perovskite NCs. Herein, we report a facile ligand-assisted synthesis to achieve lead-free Cs₃Cu₂Cl₅ NCs with a high PLQY of ∼70% and good stability against environmental oxygen/moisture as a promising down-conversion material. It has good merits of high PLQY and large Stokes shift (∼300 nm) originated from the effect of Jahn–Teller distortion and self-trapped excitons (STEs). Furthermore, the Cs₃Cu₂Cl₅ NCs embedded composite films (NCCFs) were utilized to enhance the ultraviolet (UV) response of silicon (Si) photodetectors. External quantum efficiency (EQE) measurements show that the UV response can be greatly improved from 3.3 to 19.9% @ 295 nm based on NCCFs combined with Si photodiodes. Our work offers an effective approach to develop highly efficient and stable lead-free Cs₃Cu₂Cl₅ NCs for the application in the solar-blind UV photodetector.