Seed layer effect on morphological, structural, and optical properties of electrochemically grown ZnO nanowires over different SnO 2 :F/glass substrates

Transparent conductive oxide electrodes and specifically SnO 2 :F/glass are widely employed substrates in the preparation of optoelectronic devices. This study deals with the surface effect of commercially SnO 2 :F/glass electrodes on the properties of ZnO nanowires grown onto them by using an electrochemical method. Four types of commercially SnO 2 :F/glass with sheet resistances in the range of 7–15 Ω cm −2 and roughness from 9 to 39 nm were used. The deposition process of ZnO nanowires was performed with zero, one, and two ZnO seed layers, respectively. The seed layer was grown from an ethanolic solution of zinc acetate as a Zn 2+ precursor, and further, a thermal treatment was performed. The formation of the nanomaterial was carried out by using the potentiostatic method at − 1 V and until reaching a total charge of − 1.5 C at a temperature of 75 °C. Different densities of nanowires were obtained for each case, with diameters ranging from 30 to 400 nm. The SnO 2 :F/glass roughness affects the diameter and alignment of the ZnO nanowires. Measurements of diffusive spectra in the optical range, as well as the determination of polarization properties, show that the seed layer deposition is indispensable to obtain optimal optical quality. The findings here discussed constitute another critical factor to be considered in the synthesis of well-aligned nanowires.