Optical properties 101 Energy gap 20 Zinc oxide 13 Thin films 11 optical properties 11 OPTICAL-PROPERTIES 10 Scanning electron microscopy 8 Sol-gels 8 Density functional theory 7 III-V semiconductors 7 Refractive index 7 Chlorine compounds 6 Crystal structure 6 Field emission microscopes 6 II-VI semiconductors 6 Infrared devices 6 Light absorption 6 Photoluminescence 6 Semiconductor doping 6 Sol-gel process 6 Structural properties 6 Substrates 6 Electrical and optical properties 5 Electronic equipment 5 Electronic properties 5 Electronic structure 5 Field emission scanning electron microscopy 5 Glass 5 Morphology 5 Optical films 5