Highly sensitive and wavelength-tunable solution-processed BiFeO3 heterojunction based fast-response self-powered white-light photodetector

Abstract

Herein we demonstrate the fast response of solution-processed Al-doped ZnO (AZO) /BiFeO3 (BFO) /poly (3,4-ethylenedioxythiophene) polystyrene sulfonate (PEDOT: PSS) heterojunction-based self-powered visible light tunable photodetector utilizing the ferroelectric depolarization electric field and built-in electric field at the interfaces AZO/BFO and BFO/PEDOT: PSS. The device exhibited a higher responsivity of ∼65 µA/W for the white light (intensity 100 mW/cm2) under zero bias with a response speed (rise time τr = 0.096 s and decay time τd = 0.096 s) faster than the reported BFO based devices. For 405 nm LED (intensity 10 mW/cm2), the device exhibits higher responsivity (∼1.18 mA/W) and detectivity (1.13 × 1010 Jones), with a rise and fall time of 0.186 s and 0.182 s, respectively. For 450 nm LED, the device responsivity is 1.35 × 10−4 A/W, with a rise and fall time of 0.231 s and 0.235 s, respectively. Furthermore, the device exhibit stable operations in the ambient condition even one year after fabrication. Under weak light (intensity 70 µW/cm2), it is highly sensitive and stable with a photocurrent and responsivity of ∼ 5.6 nA and ∼0.0829 mA/W, respectively. Our work is one of the promising approaches to improving the performance of solution-processed BFO-based photodetectors.