Self-powered UV photodetector based on poly (3,4-ethylenedioxyselenophene)/ZnO @ZnSe nanorods sandwich structure

In the present work, a novel self-powered hybrid ultraviolet (UV) photodetector (PD) based on ZnO @ZnSe nanoarrays/poly(3,4-ethylenedioxyselenophene) (PEDOS) was fabricated and systematically investigated. The designed PD is based on a sandwich configuration and with p-n junction, which is consisting of ZnO as the bottom n- layer, PEDOS as the top of p-layer, and ZnSe as the insertion layer. The results of the study on the performances of UV PD under different conditions optical power density shows that the ZnO@ZnSe/PEDOS exhibits excellent detection of UV light, the device achieves the excellent responsivity (R) 5.44 mA/W and high detectivity (D*) 1.42 × 10 11 Jones under the weaker optical power density (0.32 mW/cm 2 ). The study concludes with a suggestion that the ZnSe layer acts a key role in the superior property of the obtained device, which is introduction of ZnSe layer between the p-PEDOS and n-ZnO layers reduces band migration and thus effectively enhances carrier transport within them, and demonstrating that the responsivity (R) of ZnO@ZnSe/PEDOS is almost 18 times that of the device without the ZnSe layer (0.3 mA/W). On the other hand, as the p- types PEDOS, which enhances the junction quality by reducing the composite center of the carrier, expanding the depletion region and providing a step energy level between the band edges of ZnO and ZnSe, improving the overall collection of photogenerated carriers.