Growth of Aluminum Doped Zinc Oxide Nanostructure Thin Films by Nonconventional Sol‐Gel Method

Abstract

The present work demonstrates the growth of undoped and Al doped ZnO (AZO) thin films by using nonconventional sol-gel method. The structural, morphological, optical, and electrical properties of obtained thin films are studied. X-ray diffraction (XRD) analysis confirms hexagonal wurtzite structures for both undoped and doped thin films. The crystallite size is found between 15 and 30 nm. Scanning electron microscope (SEM) images show that the films have approximately uniform morphologies, consisting in several flower-like aggregates with nanosized multipetals. From the optical properties, it is found that with the increase in the doping concentration, there is a decrease in the absorption coefficient in the visible wavelength range. It is also noticed that the increase in doping concentration causes an increase in bandgap (E g ) and a decrease in extinction coefficient. Urbach energy decreases with increase in the doping concentration. In the Hall effect study, it is observed that the conductivity and carrier concentration increase sharply with increasing the aluminum quantity. The causes and significance of these observations are discussed.

Anin situ hyperconnective network strategy to prepare lanthanum zirconate nanofiber membranes with superior flexibility and toughness

“…36 When the NFM is modied by aluminum sol, another peak can be tted at 74.5 eV, which is assigned to the Al-O-H bonds. 37 The above XPS results conrm that the L5AZO NFM has been synthesized and modied successfully.…”

Effect of Al Incorporation on the Structural and Optical Properties of Sol–Gel AZO Thin Films

“…The UV band can be assigned to the near-band-edge (NBE) emission or to the related recombination of free excitons, while the visible bands are ascribed to the defects in ZnO, such as oxygen vacancies (V O ), zinc vacancies (V Zn ), Zn interstitials (Zn i ) and oxygen atoms at zinc position in crystal lattices (O Zn ) [57]. According to the literature, the performance of AZO thin films was explored by varying several parameters such as substrate [58][59][60] and solvent type [29,52], dopant concentration [34,61], annealing temperature [62] and thickness (number of layers) [31]. It was observed that the PL properties are strongly influenced by the previously mentioned factors, especially by the type of substrate used [63], amount of dopant [54][55][56] and annealing temperature [64].…”