ABSTRACT Due to the inherent bandgap limitations of traditional semiconductors, achieving a broadband response typically requires complex heterostructures, which suffer from lattice mismatch and compromised performance. Herein, we propose a novel oxygen plasma treatment WSe 2 homojunction strategy to overcome this trade‐off. A simple mask‐assisted magnetron sputtering technique was employed to fabricate an interdigital p‐n homojunction photodetector. The key innovation lies in creating a staggered type‐II band alignment via localized oxygen doping on pure WSe 2 , which effectively promotes charge separation across the broadband. The device exhibits remarkable detectivity values of 4.58×10 9 Jones (365 nm), 3.57×10 10 Jones (470 nm), 1.29×10 11 Jones (550 nm), 1.13×10 12 Jones (850 nm), and 1.52×10 12 (1064 nm) at a bias of 0 V. Clear “HIT” pixel images with distinct edges were obtained at all these wavelengths. At 1064 nm, the device achieved a high on/off ratio of 2,208 and fast rise/fall times of 59 µs and 18 µs, respectively. Through wide‐spectrum imaging and high‐frequency response testing, the device demonstrates excellent potential for next‐generation, high‐performance broadband imaging systems.
Liu et al. (Fri,) studied this question.