Fabrication of a novel low-cost triple layer system (TaZO/Ag/TaZO) with an enhanced quality factor for transparent electrode applications

Abstract

A triple layer system (TaZO/Ag/TaZO) consists of tantalum doped zinc oxide (TaZO) as the top and bottom layers and metallic silver (Ag) as the intermediate layer was deposited onto glass substrates. The top and bottom layers were deposited using an inexpensive homemade Automated Jet Nebulizer Spray Technique (AJNSP) and the intermediate Ag layer was deposited using thermal evaporation technique. Three different sets of samples with top and bottom layers having thickness values around 50, 75 and 100 nm were prepared keeping the thickness of the middle layer constant (15 nm). The influence of thickness on structural,electrical, optical and photoluminescence properties along with surface morphology of the deposited triple layer system was studied. Structural study revealed that the deposited films have hexagonal wurzite structure of ZnO and x-ray photoelectron spectroscopic study confirms the presence of the expected elements in the system. Optical studies show that the overall thickness of the films influences only marginally the transmittance of the films. The decrease in sheet resistance with the increase in thickness is explained on the basis of grain boundary scattering mechanism. Among all the films examined, the multi-layer film with 75+15+75 nm thickness exhibits best quality factor (8.98 × 10 -3 (Ω/sq.) -1 ), which may be considered as a potential candidate for transparent electrode applications. To the best of our knowledge, this is the first report in which a low cost chemical technique is employed to fabricate a triple layered system. ________________________________________________________________________________________________________________

Low-Temperature Fabrication of High-Performance and Stable GZO/Ag/GZO Multilayer Structures for Transparent Electrode Applications

“…The GAG-0 sample without any silver interlayer showed a high sheet resistance R S of 2500 Ω/sq and electrical resistivity ρ in the order of 10 −2 Ω•cm due to the low preparation temperature. The optical transmittance of GAG-0 is 88% in the visible range of wavelengths (400-700 nm), as shown in Figure 3a, which is consistent with early studies [23,26]. After covering this GZO film with the 10-nm thick Ag layer (GA sample), the resistivity decreases to 2.3 × 10 −5 Ω•cm.…”

“…Various deposition techniques have been used to produce oxide-metal-oxide structures, including thermal evaporation [24], electron beam evaporation [25], spray pyrolysis [26], sol-gel methods [27], ion beam sputtering [28], and magnetron sputtering [18][19][20]28]. Low-cost wet chemical methods are usually the starting point and benchmark for most academic and industrial processes that require a thin and uniform coating, but the transparent electrodes obtained by these techniques have resulted in inferior electrical features compared with those deposited by ion plasma methods [25,29,30].…”