As a p-type elemental material with high carrier mobility, superior ambient stability, and anisotropic crystal structure, emerging two-dimensional (2D) tellurium (Te) has been considered a successor to black phosphorus for developing infrared-related optoelectronics. Nevertheless, the lack of a scalable thickness engineering strategy remains an obstacle to unleashing its full potential. Te-based electronics with logic functions are also less explored. Herein, we propose a novel wet-chemical thinning method for 2D Te, with the merits of scalability and site-specific thickness patterning capability. A polarity-switchable van der Waals (vdW) heterodiode with a high rectification ratio of 2.4 × 103 is realized on the basis of Te/WSe2. The electronic application of this unique characteristic is demonstrated by fabricating a logic half-wave rectifier, in which the rectifying states are switchable via electrostatic gating control. Besides, the narrow band gap of Te endows the device with a broad spectral response from visible to short-wave infrared. The room-temperature responsivity reaches 5.2 A W–1 at the telecom wavelength of 1.55 μm, with an external quantum efficiency of 420% and detectivity of 6.8 × 109 Jones. In particular, owing to the intrinsic in-plane anisotropy of Te, the device exhibits a favorable photocurrent anisotropic ratio of ∼3. Our study demonstrates the enormous potential of Te for novel electronics, promoting the development of elemental 2D materials.

Research on elemental 2D materials has been experiencing a renaissance in the past few years. Of particular interest is tellurium (Te), which possesses many exceptional properties for nanoelectronics, photonics, and beyond. Nevertheless, the lack of a scalable approach for the thickness engineering and the local properties modulation remains a major obstacle to unleashing its full device potential. Herein, a solution-processed oxidative etching strategy for post-growth thickness engineering is proposed by leveraging the moderate chemical reactivity of Te. Large-area ultrathin nanosheets with well-preserved morphologies could be readily obtained with appropriate oxidizing agents, such as HNO2, H2O2, and KMnO4. Compared with the conventional physical thinning approaches, this method exhibits critical merits of high efficiency, easy scalability, and the capability of site-specific thickness patterning. The thickness reduction leads to substantially improved gate tunability of field-effect transistors with an enhanced current switching ratio of ∼103, promoting the applications of Te in future logic electronics. The response spectrum of Te phototransistors covers the full range of short-wave infrared wavelength (1–3 μm), and the room-temperature responsivity and detectivity reach 0.96 AW-1 and 2.2 × 109 Jones at the telecom wavelength of 1.55 μm, together with a favorable photocurrent anisotropic ratio of ∼2.9. Our study offers a new approach to tackling the thickness engineering issue for solution-grown Te, which could help realize the full device potential of this emerging p-type 2D material.