Effects of Al Concentration on Structural and Optical Properties of Al-doped ZnO Thin Films

Abstract

Aluminium (Al)-doped zinc oxide (AZO) thin films with different Al concentrations were prepared by the solgel spin-coating method. Optical parameters such as the optical band gap, absorption coefficient, refractive index, dispersion parameter, and optical conductivity were studied in order to investigate the effects of the Al concentration on the optical properties of AZO thin films. The dispersion energy, single-oscillator energy, average oscillator wavelength, average oscillator strength, and refractive index at infinite wavelength of the AZO thin films were found to be affected by Al incorporation. The optical conductivity of the AZO thin films also increases with increasing photon energy.

Optical properties and electrical resistivity of boron-doped ZnO thin films grown by sol–gel dip-coating method

“…The refractive index dispersion plays an important role in optical communications and in designing optical devices. Thus, it is important to determine the dispersion parameters for the thin films, for which we used the Wemple and DiDomenico model as follows [47]: The dispersion data for the refractive index were also fitted using the following relation [6]: …”

“…However, ITO-based materials are very expensive and toxic and exhibit low stability to H 2 plasma. Zinc oxide (ZnO) has recently attracted attention as a TCO because it exhibits a wide band gap (3.37 eV), and a high exciton binding energy (60 meV) at room temperature (RT) [4], it is easy to dope using various elements, it is thermally stable when doped with group III elements [5], it exhibits better resistance to damage during H 2 plasma processing than ITO does [6,7]. Thus, group III elements such as B [8,9], Al [10,11], Ga [12,13], and In [14,15] can be readily used as cation dopants to improve the optical properties of ZnO thin films.…”

Investigation of characteristics of ZnO:Ga nanocrystalline thin films with varying dopant content

“…The total stress is made up of two components. The first is intrinsic stress, which consists of impurities and defects, and the second is extrinsic stress, which is formed by the lattice mismatch in the lattice constants and the thermal expansion coefficient of the films and substrates [36][37][38]. In this context, we can be clear that pre and post-heat processes were kept the same for all samples.…”

Surface plasmon resonance in nanostructured Ag incorporated ZnS films

“…The decrease in the refractive index with Ag incorporation can be attributed to an increase in the carrier concentration in the Ag incorporated thin films. 51 The refractive index seems to be a significant factor for photocurrent of the photoelectrode; the smaller the value of this refractive index, the better the performance of the photoelectrode is. The optical response of a material is mainly studied in terms of the optical conductivity (σ) which is given by the relation.…”