Metal–Semiconductor–Metal Ultraviolet Photodetectors Based on Zinc-Oxide Colloidal Nanoparticles

Abstract

Metal-semiconductor-metal ultraviolet (UV) photodetectors were created with zinc-oxide colloidal nanoparticles coated with polyvinyl-alcohol. Gold-interdigitated finger contacts with different parameters were patterned on the nanoparticles by optical lithography. The photodetectors exhibited UV-photogenerated current to dark current ratios ranging from 3.85 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">6</sup> to 1.34 × 10 <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">8</sup> , depending on the finger parameters. The spectral responses demonstrate a 375 nm cutoff wavelength, with a peak responsivity of 731.42 A/W at 345 nm.