Enhanced ultraviolet sensitivity of zinc oxide nanoparticle photoconductors by surface passivation

0925-3467/$ see front matter 2010 Elsevier B.V. A doi:10.1016/j.optmat.2010.09.020 ⇑ Corresponding author. Tel.: +1 518 276 2164; fax E-mail address: [email protected] (S. Sawyer). Zinc oxide nanoparticles were created by a top-down wet-chemical etching process and then coated with polyvinyl-alcohol (PVA), exhibiting sizes ranging from 10 to 120 nm with an average size approximately 80 nm. The PVA layer provides surface passivation of zinc oxide nanoparticles. As a result of PVA coating, enhancement in ultraviolet emission and suppression of parasitic green emission is observed. Photoconductors fabricated using the PVA coated zinc oxide nanoparticles exhibited a ratio of ultraviolet photogenerated current to dark current as high as 4.5 10, 5 times better than that of the devices fabricated using uncoated ZnO nanoparticles. 2010 Elsevier B.V. All rights reserved.