UV to NIR Broadband Flexible Photodetector Based on Solution-Processed MoS2/PDPP3T Inorganic–Organic Hybrid Heterostructures

Molybdenum disulfide (MoS₂) is a 2D material with excellent electrical and optical properties, and developing a universal technology for the preparation of high-performance MoS₂-based photodetector is extremely desirable. Here, a UV to NIR broadband flexible photodetector based on MoS₂/(PDPP3T) inorganic–organic hybrid heterostructures is reported. In the experiment, high crystalline 2H-phase few-layer MoS₂ nanoflakes are first prepared by optimized electrochemical intercalation of tetraheptylammonium cation (THA⁺) and ultrasound-assisted exfoliation strategy. Thereafter, a narrow bandgap organic semiconductor PDPP3T is introduced to construct the MoS₂/Poly(diketopyrrolopyrrolothiophrn) (PDPP3T) heterojunction. Experimental results reveal that the photodetector can have broadband photo response from 380 to 980 nm. Meanwhile, excellent responsivities and detectivity of 12.4 mA W⁻¹, 2.2 × 10¹⁰ Jones at 380 nm and 0.1 mA W⁻¹ and 5 × 10⁸ Jones at 980 nm are achieved, which are ≈10 (UV band)/100 (NIR band) times high than that obtained on the pure MoS₂-based detector. Moreover, the flexibility of the device is investigated by conformal covering the device on a curved surface (R = 5 and 2.5 mm), it shows that the photo response remains almost the same as that measured on the planar substrate, indicating the possible application in the wearable electronics.