Chemical bath deposition of CdS channel layer for fabrication of low temperature-processed thin-film-transistors

Abstract

similar to 66 nm thick CdS film with a hexagonal structure was uniformly generated via a low temperature-processed chemical bath deposition at 80 degrees C using a complexing agent of ethylenediaminetetraacetic acid and its crystal structure, surface morphology, optical transmittance, and Raman scattering property were measured. Grown CdS film was used as a channel layer for the fabrication of bottom-gate, top-contact thin-film-transistor (TFT). The TFT device with 60 degrees C-dried channel layer exhibited a poor electrical performance of on-to-off drain current ratio (I-on/I-off) of 5.1 x 10(3) and saturated channel mobility (mu(sat)) of 0.10 cm(2)/Vs. However, upon annealing at 350 degrees C, substantially improved electrical characteristics resulted, showing I-on/I-off of 5.9 x 10(7) and mu(sat) of 5.07 cm(2)/Vs. Furthermore, CdS channel layer was chemically deposited in an identical way on a transparent substrate of SiNx/ITO/glass as part of transparent TFT fabrication, resulting in I-on/I-off of 5.8 x 10(7) and mu(sat) of 2.50 cm(2)/Vs. (C) 2012 Elsevier B.V. All rights reserved.