Ultrahigh‐Performance Broadband Photodetection in NiTeSe–WS2 Heterostructures: A Synergistic Integration of Dirac Semimetals and 2D TMDs

2D transition metal dichalcogenides (2D TMDs) like WS2 have shown immense potential for optoelectronic applications but face inherent limitations in spectral range, carrier mobility, and recombination losses. To overcome these challenges, a novel heterostructure combining WS2 with the semimetal NiTeSe is proposed, leveraging its ultrahigh carrier mobility and near‐zero bandgap for enhanced photodetection. Through first‐principles density functional theory (DFT) calculations and COMSOL Multiphysics simulations, the electronic and optical properties of the NiTeSe–WS2 heterostructure are systematically investigated. The hybrid system has a Schottky barrier at the interface and a smaller bandgap (0.689 eV in NiTeSe–WS2 compared to 1.809 eV in pure WS2). This helps separate charges more efficiently and absorb a wider range of light. Optical analyses reveal exceptional performance, including a 48% higher absorption coefficient (2.21 × 10⁵ cm−1) and 53% enhanced optical conductivity (3.91 Ω−1 cm−1) compared to pristine WS2. Device simulations reveal outstanding photoresponse performance, with a peak responsivity of 4.3 × 104 A W−1 and an external quantum efficiency of 1.06 × 105%, representing a significant enhancement compared to pristine WS2. These results establish the NiTeSe–WS2 heterostructure as a transformative platform for next‐generation photodetectors, offering unprecedented sensitivity, spectral versatility, and speed for applications in communication, imaging, and sensing technologies.