The thin layers of ZnO and ZnO: Al (Al doped zinc oxide—AZO) were deposited by the atomic deposition layer (ALD) method on silicon and glass substrates. The structures were deposited using diethylzinc (DEZ) and deionized water as zinc and oxygen precursors. A precursor of trimethylaluminum (TMA) was used to introduce the aluminum dopant. The present study of ALD-deposited ZnO and AZO films was motivated by their applications in photovoltaics. We attempted to expose several properties of such films. Structural, optical (including ellipsometric measurements) and electrical investigations were performed. We discussed the relations between samples doped with different Al fractions and their properties.
One of the important research directions in the field of photovoltaics is integration with construction. The integration of solar cell systems with a building can reduce installation costs and help optimize the used space. Among the few literature reports on photovoltaic roof tiles, solutions with silicon and thin film solar cells dominate. An interesting solution may be the application of dye-sensitized solar cells. In addition to their interesting properties, they also have aesthetic value. In the classic arrangement, they are constructed using glass with a transparent conductive layer (TCL). This article describes replacing a classic glass counter electrode with an electrode based on a ceramic tile and nickel foil. First, a continuous and homogeneous fluorine-doped tin oxide (FTO) thin film was developed so that the above-mentioned substrate could be applied. The atomization method was used for this purpose. Then, nanocolloidal platinum paste was deposited as a catalytic material using the screen printing method. The electrical parameters of the manufactured DSSCs with and without a counter electrode tile were characterized by measuring their current–voltage characteristics under standard AM 1.5 radiation. A dye-sensitized solar cell integrated with ceramic tiles and nickel foil was produced and displayed an efficiency of over 4%. This solution makes it possible to expand their construction applications. The advantage of this solution is full integration with construction, while simultaneously generating electricity. A dye-sensitized solar cell was built layer-by-layer on a ceramic tile and nickel foil.
1 March 2020 in International Journal of Nanomedicine
Introduction: The development of the field of biomaterials engineering is rapid. Various bioactive coatings are created to improve the biocompatibility of substrates used for bone regeneration, which includes formulation of thin zirconia coatings with pro-osteogenic properties. The aim of this study was to assess the biological properties of ZrO2 thin films grown by Atomic Layer Deposition (ALD) technology (ZrO2ALD). Methodology: The cytocompatibility of the obtained layers was analysed using the mice pre-osteoblastic cell line (MC3T3) characterized by decreased expression of microRNA 21-5p (miR-21-5p) in order to evaluate the potential pro-osteogenic properties of the coatings. The in vitro experiments were designed to determine the effect of ZrO2ALD coatings on cell morphology (confocal microscope), proliferative activity (cell cycle analysis) and metabolism, reflected by mitochondrial membrane potential (cytometric-based measurement). Additionally, the influence of layers on the expression of genes associated with cell survival and osteogenesis was studied using RT-qPCR. The following genes were investigated: B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein (Bax), p53 and p21, as well as osteogenic markers, i.e. collagen type 1 (Coll-1), osteopontin (Opn), osteocalcin (Ocl) and runt-related transcription factor 2 (Runx-2). The levels of microRNA (miRNA/miR) involved in the regulation of osteogenic genes were determined, including miR-7, miR-21, miR-124 and miR-223. Results: The analysis revealed that the obtained coatings are cytocompatible and may increase the metabolism of pre-osteoblast, which was correlated with increased mitochondrial membrane potential and extensive development of the mitochondrial network. The obtained coatings affected the viability and proliferative status of cells, reducing the population of actively dividing cells. However, in cultures propagated on ZrO2ALD coatings, the up-regulation of genes essential for bone metabolism was noted. Discussion: The data obtained indicate that ZrO2 coatings created using the ALD method may have pro-osteogenic properties and may improve the metabolism of bone precursor cells. Given the above, further development of ZrO2ALD layers is essential in terms of their potential clinical application in bone regenerative medicine.
Low temperature (at 100 °C and below) growth of ZnO thin films by atomic layer deposition (ALD) is demonstrated. Properties of the layers grown with two different oxygen reagents: ozone and water are compared. Diethylzinc (DEZ) was used as metal precursor. Electrical and structural properties of films obtained at several different growth temperatures, ranging from 50 °C to 250 °C were analyzed. It turned out that the film grown in the water-based process at 250 °C and all films grown with ozone have more ordered crystallographic structure with the privileged growth direction (001) perpendicular to the substrate than water-based samples grown in temperatures 100–200 °C. Higher free electron concentration at room temperature was observed for ozone-based samples grown at 100 °C and 150 °C in comparison to water-based samples obtained at the same growth temperature. Low value of resistivity in case of ozone-based samples grown at 100 °C is a promising result, however lower electron mobility requires further optimization.
14 February 2014 in Beilstein Journal of Nanotechnology
Selected properties of photovoltaic (PV) structures based on n-type zinc oxide nanorods grown by a low temperature hydrothermal method on p-type silicon substrates (100) are investigated. PV structures were covered with thin films of Al doped ZnO grown by atomic layer deposition acting as transparent electrodes. The investigated PV structures differ in terms of the shapes and densities of their nanorods. The best response is observed for the structure containing closely-spaced nanorods, which show light conversion efficiency of 3.6%.
1 September 2021 in Solar Energy Materials and Solar Cells