Broadband and High‐Performance Photodetector Fabricated Using Large Area and Transfer‐Free 2D–2D PtS₂/MoS₂ Heterostructure

Abstract 2D transitional metal dichalcogenide (TMDC) materials have shown great potential in the optoelectronics and electronics field owing to their unique and favorable properties. However, developing high‐performance broadband photodetectors in bare TMDC material is impeded due to their limited absorption and poor charge‐carrier separation. The recent advancement in van der Waals heterostructure fabrication has exhibited a new path to improve the device performance. In the present work, a facile approach is presented to fabricate a large area of PtS₂/MoS₂ heterostructure, which demonstrates a broad spectral detection range from 400 to 1200 nm with high responsivity (30.2 A W⁻¹) and detectivity (1.12 × 10¹³ Jones) even under near‐infrared (NIR) 900 nm light illumination at moderate bias. Moreover, the PtS₂/MoS₂ photodetector exhibits a much enhanced responsivity (97 times) and detectivity (33 times) compared with bare MoS₂. A rise/fall time of 11 ms/10 ms for the PtS₂/MoS₂ device represents its fast response speed. The X‐ray photoelectron spectroscopy measurements reveal the type‐I band alignment between the PtS₂ and MoS₂, which are further utilized to understand the charge carrier dynamics between the PtS₂ and MoS₂ interface. This work presents a simple strategy to synthesize scalable, high‐performance broadband photodetectors for future optoelectronics applications.