Eco-friendly Ag2S QDs/PDPP3T inorganic-organic hybrid heterostructures for broadband photodetection

Abstract

Photodetectors featuring broadband detection capability, along with a facile and environmentally friendly preparation process, are critical and highly desirable for diverse optoelectronic applications. Herein, an environmentally friendly, easily fabricated Ag₂S QDs/PDPP3T inorganic-organic hybrid heterojunction was constructed to develop the 0D/2D broadband photodetector. In the experiment, the Ag₂S QDs were first synthesized by a microwave-heating method, and the photoresponse of the pure Ag₂S QDs detector was optimized via tuning the microwave power and reactant ratio. Subsequently, the PDPP3T was deposited on the Ag₂S QDs thin film to construct the heterostructure, aiming to further enhance the photo-sensing performance. The measurement results revealed that the device exhibited excellent performance within the visible to near-infrared wavelength region. Under laser illumination at 400, 532, and 900 nm, the responsivity, detectivity, and external quantum efficiency (EQE) reached 274.3 A/W, 4.62 × 10¹³ Jones, 849.4%; 225.8 A/W, 3.79 × 10¹³ Jones, 524.4%; and 280.7 A/W, 4.72 × 10¹³ Jones, 429.7%, respectively. Whereas the maximum responsivity, detectivity and EQE of the device reach 393.4 A/W 6.62 × 10¹³ Jones and 871%, respectively, which were measured at a wavelength of 700 nm. Moreover, the detector also demonstrated excellent response dynamics, with rise/fall times of 33.6/45.1 ms. In essence, these achievements were attributed to the enhanced light absorption of PDPP3T and optimized band alignment, which ultimately facilitated efficient carrier separation and collection.