Abstract:
Zinc oxide (ZnO) is one of the most promising metal oxide semiconductor materials, particularly for
optical and gas sensing applications. The infuence of thickness and solvent on various features of
ZnO thin flms deposited at ambient temperature and barometric pressure by the sequential ionic
layer adsorption and reaction method (SILAR) was carefully studied in this work. Ethanol and distilled
water (DW) were alternatively used as a solvent for preparation of ZnO precursor solution. Superfcial
morphology, crystallite structure, optical and electrical characteristics of the thin flms of various
thickness are examined applying X-ray difraction (XRD) system, scanning electron microscopy,
the atomic force microscopy, X-ray photoelectron spectroscopy, ultraviolet–visible spectroscopy,
photoluminescence spectroscopy, Hall efect measurement analysis and UV response study. XRD
analysis confrmed that thin flms fabricated using ethanol or DW precursor solvents are hexagonal
wurtzite ZnO with a preferred growth orientation (002). Furthermore, it was found that thin flms
made using ethanol are as highly crystalline as thin flms made using DW. ZnO thin flms prepared
using aqueous solutions possess high optical band gaps. However, flms prepared with ethanol solvent
have low resistivity (10–2 Ω cm) and high electron mobility (750 cm2
/Vs). The ethanol solvent-based
SILAR method opens opportunities to synthase high quality ZnO thin flms for various potential
applications.
