Flexible ultraviolet photodetectors with ZnO nanowire networks fabricated by large area controlled roll-to-roll processing

Abstract

Ultraviolet (UV) photodetectors containing flexible films were fabricated by a roll-to-roll processing method. Gravure printing and slot-die coating techniques were utilized for manufacturing Ag sensing electrodes and Zn acetate seeds, respectively, while well-organized Zn oxide nanowire networks with a high density were grown hydrothermally on flexible substrates. The maximum photocurrent of 62.1 μA, a response time of 9.1 s, and a recovery time of 56 s were obtained at a bias voltage of 10 V under UV irradiation with a density of 127 μW cm⁻². The resulting correlation between the seeding rate, the nanowire diameter, and the photocurrent indicates that high seeding rates lead to the formation of dense nanowire structures and excellent response times.