Few‐layer black phosphorus (FL‐BP) is a promising high‐mobility semiconductor with thickness‐dependent direct bandgap varying from visible to mid‐infrared region. The poor stability under harsh environment, stemming from irreversible oxidization of P atoms with lone pair electrons, restricts its practical applications. Herein, an electrochemical intercalation and in situ electrochemical deposition (EI&ED) approach to produce scalable Au nanoparticles/FL‐BP crystals with enhanced stability in harsh environment is developed. In this approach, the chemical reactivity of BP is significantly suppressed via the efficient local charge transfer from FL‐BP to electrochemically deposited Au nanoparticles. Thus obtained Au/FL‐BP based nano‐devices show good stability under harsh environment, including i) high humidity of 95%, ii) immersibility in organic agents for as long as 45 days, and iii) annealing at 573 K for 9 h. In addition, compared to bare FL‐BP crystals, Au/FL‐BP based photodetectors present 50‐ and 36‐fold improvement of photoresponsivity at 1550 and 1850 nm via the surface plasmonic enhancement effect. This EI&ED method can produce ultra‐stable FL‐BP crystals at large‐scale, which resolves the crucial barriers in using FL‐BP in large‐scale electronic and optoelectronic devices.

A main challenge for the development of two‐dimensional devices based on atomically thin transition‐metal dichalcogenides (TMDs) is the realization of metal–semiconductor junctions (MSJs) with low contact resistance and high charge transport capability. However, traditional metal–TMD junctions usually suffer from strong Fermi‐level pinning (FLP) and chemical disorder at the interfaces, resulting in weak device performance and high energy consumption. By means of high‐throughput first‐principles calculations, we report an attractive solution via the formation of van der Waals (vdW) contacts between metallic and semiconducting TMDs. We apply a phase‐engineering strategy to create a monolayer TMD database for achieving a wide range of work functions and band gaps, hence offering a large degree of freedom to construct TMD vdW MSJs with desired contact types. The Schottky barrier heights and contact types of 728 MSJs have been identified and they exhibit weak FLP (−0.62 to −0.90) as compared with the traditional metal–TMD junctions. We find that the interfacial interactions of the MSJs bring a delicate competition between the FLP strength and carrier tunneling efficiency, which can be utilized to screen high‐performance MSJs. Based on a set of screening criteria, four potential TMD vdW MSJs (e.g., NiTe2/ZrSe2, NiTe2/PdSe2, HfTe2/PdTe2, TaSe2/MoTe2) with Ohmic contact, weak FLP, and high carrier tunneling probability have been predicted. This work not only provides a fundamental understanding of contact properties of TMD vdW MSJs but also renders their huge potential for electronics and optoelectronics.

Heteroepitaxy of high-quality GaN-based heterostructures with tunable band alignment and optical properties is of central importance for their applications in electronics and optoelectronics. Incommensurate material growth on GaN substrate with...

Van der Waals (vdW) metal–semiconductor junctions (MSJs) exhibit huge potential to reduce the contact resistance and suppress the Fermi‐level pinning (FLP) for improving the device performance, but they are limited by optional (2D) metals with a wide range of work functions. Here a new class of vdW MSJs entirely composed of atomically thin MXenes is reported. Using high‐throughput first‐principles calculations, highly stable 80 metals and 13 semiconductors are screened from 2256 MXene structures. The selected MXenes cover a broad range of work functions (1.8–7.4 eV) and bandgaps (0.8–3 eV), providing a versatile material platform for constructing all‐MXene vdW MSJs. The contact type of 1040 all‐MXene vdW MSJs based on Schottky barrier heights (SBHs) is identified. Unlike conventional 2D vdW MSJs, the formation of all‐MXene vdW MSJs leads to interfacial polarization, which is responsible for the FLP and deviation of SBHs from the prediction of Schottky–Mott rule. Based on a set of screening criteria, six Schottky‐barrier‐free MSJs with weak FLP and high carrier tunneling probability (>50%) are identified. This work offers a new way to realize vdW contacts for the development of high‐performance electronic and optoelectronic devices.

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