High-performing ultrafast transparent photodetector governed by the pyro–phototronic effect

Abstract

In this work we utilized the advantage of the photo-induced pyroelectric effect – known as “Pyro–phototronic” – to design a self-powered, ultrafast, transparent ultraviolet (UV, 365 nm) photodetector. The device architecture contains an UV absorbing pyroelectric ZnO layer sandwiched between hole-selective V₂O₅ and a bottom ITO electrode. In addition, the device shows a high optical transmittance, >70%, in the entire visible region. The photo current of the device was enhanced from 19 to 42 μA under pulsed UV light illumination (λ = 365 nm, 4 mW cm⁻²) by exploiting the pyro–phototronic potential. In addition, the photodetector demonstrated ultrafast responses of ∼4 μs for the rise time and ∼16 μs for the fall time. Further, a high photoresponsivity of ∼36.34 mA W⁻¹ and excellent photodetectivity of ∼6.04 × 10¹⁴ Jones, with an enhancement of 725% in both due to the pyroelectric potential, were measured. This novel approach will open a new path to design transparent and ultrafast devices, as well as on the flexible substrates, for future optoelectronic applications.