Electronic equipment 2 Energy gap 2 Sol-gel process 2 Sol-gels 2 Thermoelectric equipment Thin films Absorbance measurements 1 Absorbances 1 Annealing temperatures 1 Atomic force microscopy 1 Best value 1 Coatings 1 Current voltage 1 Direct band gap 1 Enamels 1 Field emission microscopes 1 Field emission scanning electron microscopy 1 Film preparation 1 Film thickness 1 Molarity 1 Optical band gaps 1 Optical characteristics 1 Optical emission spectroscopy 1 Optical properties 1 Precursor solutions 1 Quartz substrate 1 Scanning electron microscopy 1 Sol gel dip coating 1 Sol-gel dip coating technique 1 Sol-gel spin coating 1