Construction and properties of ZnO/poly(EDOT-Pyridine-EDOT) core/shell heterostructure nanoarrays for UV photodetector

Here, the ZnO-NRs/poly(EDOT-Pyridine-EDOT) core/shell heterostructure nanoarrays was prepared by the electrochemical polymerization of D-A-D type monomer (the 3,4-ethylenedioxythiophene(EDOT, donor) endcapped trimer with the pyridine(acceptor) as internal unit) on ZnO-NRs. This core/shell heterostructure nanoarrays was combined with ZnO-NRs to form p-n heterojunction for UV photodetector by face to face clamping of the two electrodes (ZnO-NRs/poly(EDOT-Pyridine-EDOT) and ZnO-NRs). The current-voltage and current-time curves under bias voltages of 1–6 V were tested, and the photoresponses of heterojunctions and bias voltages to UV light irradiation were systematically studied. The results showed that the poly(EDOT-Pyridine-EDOT) (poly(BPE)) uniformly covered ZnO-NRs and formed a core-shell structure, which was beneficial to increase the contact area between ZnO-NRs and poly(BPE). The ZnO-NRs/poly(BPE) heterojunction effectively improved the response performance of the UV photodetector and exhibited the highest photoresponsivity under 5 V bias voltage. The responsivity (R), detectivity (D*) and external quantum efficiency (EQE) were 150.87 A/W, 2.18 × 10 12 Jones and 51,351.5 %, respectively.