6533b852fe1ef96bd12ab511

RESEARCH PRODUCT

Refractive index controlled by film morphology and free carrier density in undoped ZnO through sol-pH variation

A. El HamidiAhmed LibaPedro AmorósTariq JannaneJ. El HaskouriK. MezianeA. El HichouA. Almaggoussi

subject

010302 applied physicsSpin coatingMaterials scienceMorphology (linguistics)Analytical chemistry02 engineering and technologySubstrate (electronics)Molar absorptivity021001 nanoscience & nanotechnology01 natural sciencesAtomic and Molecular Physics and OpticsElectronic Optical and Magnetic MaterialsWavelength0103 physical sciencesSurface roughnessElectrical and Electronic EngineeringExponential decay0210 nano-technologyRefractive index

description

Abstract Zinc oxide thin films, prepared by the sol-gel process, were deposited on glass substrate using spin coating technique. The sol-pH effect on the optical parameters was studied for alkaline sol. The surface roughness was investigated by atomic force microscopy (AFM) and varied from 20 to 40 nm. The optical transmission measurements were carried out to evaluate the behavior of the extinction coefficient and the refractive index. An exponential decay of the refractive index ‘n’ as a function of wavelength was observed. The refractive index increases slightly when the pH increases to pH = 9.5 where it reaches its maximum. Beyond this value, it decreases sharply. This behavior has been linked to the effects of free carrier density and the films morphology. Thus, a linear variation of the refractive index as a function of surface roughness has been demonstrated.

yearjournalcountryeditionlanguage
2018-04-01Optik
https://doi.org/10.1016/j.ijleo.2018.01.011