Room-Temperature Wafer-Scale Growth of 1T′-MoTe2 for Self-Powered Broadband and Polarization-Sensitive Photodetection toward Optical Communication

Abstract

The scalable integration of two-dimensional (2D) semiconductors into next-generation optoelectronics demands moderate-temperature, wafer-scale synthesis routes compatible with industrial manufacturing. Here, we report the room-temperature growth of wafer-scale 1T′-MoTe2 thin films via industrial-standard RF magnetron sputtering, establishing a simple and scalable approach for high-performance optoelectronic devices. Systematic optimization of RF power, deposition pressure, and growth time enables the realization of highly crystalline 1T′-MoTe2. Raman spectroscopy confirms phase purity, high crystallinity, and polarization-dependent response, while large-area uniformity is demonstrated across a 2-inch wafer through spatial Raman mapping. The films exhibit a smooth and homogeneous morphology, while X-ray photoelectron spectroscopy reveals a self-limiting surface oxide layer that passivates the film and facilitates self-powered photodetection through an intrinsic built-in electric field. Photodetectors fabricated using 1T′-MoTe2 films exhibit broadband self-powered photoresponse spanning from UV to near-infrared wavelengths (300–1550 nm), with a peak responsivity of 1.4 mA W–1 and a detectivity of 7.8 × 109 Jones at zero bias. Additionally, the devices demonstrate polarization-sensitive photoresponse with an anisotropy ratio of 2, along with imaging and optical communication capabilities, and exhibit excellent operational and ambient stability. These findings position room-temperature sputtered 1T′-MoTe2 as a promising platform for scalable, low-power, and multifunctional optoelectronic technologies.