Effects of Thallium–Aluminum‐Codoped Zinc Oxide Thin Film as a New Transparent Conducting Oxide

Abstract

Herein, the electro–optical properties of sol–gel spin‐coated “thallium–aluminum‐codoped zinc oxide (TAZO)” focusing on the effects of thallium are investigated. It is shown that the amount of thallium (Tl) has a significant effect on improving the electrical properties of TAZO as a new transparent conducting oxide (TCO). The optimum results are achieved by adding 1 at% of Tl to aluminum‐doped zinc oxide (AZO), after which the sheet resistance (Rs) value is reduced from 30.21 to 2.832 KΩ sq−1. Although less Rs is recorded in all amounts of Tl used (from 1 to 4 at%) than in Tl‐free samples, Rs also increases as the amount of Tl increases, which is related to the degradation of the crystal structure at higher values of Tl. In view of a trade‐off between electrical conductivity and optical transparency, a decrease in transparency in the presence of Tl is a predictable issue, but while the Tl‐free samples record 90% transparency, the uniform thin film of 1 at% Tl‐AZO is able to achieve 85% transparency. This small amount of reduction in transparency shows the high potential of Tl to improve the properties of AZO as a TCO.

Structural, Optical, and Electrical Properties of Hafnium–Aluminum–Zinc-Oxide Films Grown by Atomic Layer Deposition for TCO Applications

“…Here, the assumption that ZnO bands are approximately parabolic is implemented. This assumption is according to many reports correct for low dopant concentrations. ,, The Tauc plots are shown in Figure .…”

“…Also, pairs such as Al/Sn, Al/Ti, Al/Th, or Al/Mn were reported to exhibit exceptional optoelectrical parameters, offering one additional degree of freedom in material design. Research findings also indicate beneficial results of codoping using two elements from different groups, such as IIIA and IVB. − Combining elements from those two groups may lead to enhanced electrical stability and further promote the mobility and concentration of the carriers in the material.…”

Exploring secondary optical transitions: a study utilizing the DITM method, and enhanced photocatalytic properties in Ni-doped CuSe

“…The sharper peak in Ni-doped CuSe, in comparison to CuSe, suggests that the presence of Ni contributes to a higher crystalline quality of CuSe due to higher degree of order, crystallization and arrangement by filling the vacancies in the lattice network 33 – 38 . Additionally, the larger ionic radius of Ni, leading to increased spacing between crystal planes during the replacement of Cu with Ni, is another factor contributing to a larger crystalline size after doping 39 – 41 . In this regard, by calculating the Scherrer’s equation (D = Kλ/βCosθ) in which D represents the crystallite size, K is a constant known as the shape factor (equal to 0.9), λ is the wavelength of X-ray radiation (1.54 Å), β is the Full Width at Half Maximum (FWHM) based on 2θ in radians, and θ in cosθ is related to the XRD peak position as Bragg's diffraction angle (θ = 2θ/2 in radians), the crystallite sizes in the CuSe and 0.3 mol Ni–CuSe samples after 6 h of annealing (Fig.…”

Al-Doped ZnO Thin Films with 80% Average Transmittance and 32 Ohms per Square Sheet Resistance: A Genuine Alternative to Commercial High-Performance Indium Tin Oxide

“…During the last decades, transparent conducting oxides (TCOs) have been considered attractive materials in different areas due to their high electrical conductivity and large transparency in the visible and near-infrared regions of the electromagnetic spectrum [1][2][3][4]. TCOs are used in a wide variety of devices, e.g., in solar cells, light-emitting diodes (LEDs), organic light-emitting diodes (OLEDs), liquid crystal displays, touch screens, photothermal conversion systems, and intelligent windows [5][6][7][8][9][10][11].…”

“…ZnO:Al thin films have been grown using a wide variety of deposition techniques, including sputtering [12], laser pulse deposition [10], electron beam evaporation [20,21], spin coating [4], sol-gel [7], pneumatic spray pyrolysis [22] and ultrasonic spray pyrolysis [6,23]. Vacuum-dependent techniques allow the deposition of ZnO:Al TCOs with low resistivities and high transparencies; unfortunately, they are expensive technologies to purchase and maintain.…”