The applications of any two-dimensional (2D) semiconductor devices cannot bypass the control of metal-semiconductor interfaces, which can be severely affected by complex Fermi pinning effects and defect states. Here, we report a near-ideal rectifier in the all-2D Schottky junctions composed of the 2D metal 1 T′-MoTe2 and the semiconducting monolayer MoS2. We show that the van der Waals integration of the two 2D materials can efficiently address the severe Fermi pinning effect generated by conventional metals, leading to increased Schottky barrier height. Furthermore, by healing original atom-vacancies and reducing the intrinsic defect doping in MoS2, the Schottky barrier width can be effectively enlarged by 59%. The 1 T′-MoTe2/healed-MoS2 rectifier exhibits a near-unity ideality factor of ~1.6, a rectifying ratio of >5 × 105, and high external quantum efficiency exceeding 20%. Finally, we generalize the barrier optimization strategy to other Schottky junctions, defining an alternative solution to enhance the performance of 2D-material-based electronic devices.

No abstract

Ultrathin 2D semiconductor devices are considered to have beyond‐silicon potential but are severely troubled by the high Schottky barriers of the metal–semiconductor contacts, especially for p‐type semiconductors. Due to the severe Fermi‐level pinning effect and the lack of conventional semimetals with high work functions, their Schottky hole barriers are hardly removed. Here, an all‐van‐der‐Waals barrier‐free hole contact between p‐type tellurene semiconductor and layered 1T′‐WS2 semimetal is reported, which achieves a zero Schottky barrier height of 3 ± 9 meV and a high field‐effect mobility of ≈1304 cm2 V–1 s–1. The formation of such contacts can be attributed to the higher work function of ≈4.95 eV of the 1T′‐WS2 semimetal, which is in sharp contrast with low work function (4.1–4.7 eV) of conventional semimetals. The study defines an available strategy for eliminating the Schottky barrier of metal–semiconductor contacts, facilitating 2D‐semiconductor‐based electronics and optoelectronics to extend Moore's law.

No abstract

No abstract