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Fabrication of Nanostructured Thin Films Using Microreactors
Published in James E. Morris, Kris Iniewski, Graphene, Carbon Nanotubes, and Nanostructures, 2017
Chih-hung Chang, Brian K. Paul, Si-Ok Ryu
Chemical bath deposition (CBD) is an aqueous analogue of chemical vapor deposition (CVD). The constituent ions are dissolved in an aqueous solution, and the thin films are produced through a heterogeneous surface reaction. A fundamental understanding of CBD, however, is far less developed than that of CVD. This has limited the development and application of this growth technique. CBD is normally carried out as a batch process in a beaker and involves both heterogeneous and homogeneous reactions. Furthermore, the bath conditions change progressively as a function of time. It is known that CBD is capable of producing an epitaxial layer on a single crystal surface. Many compound semiconductors that are major candidates for solar energy utilization have been deposited by CBD, such as CdSe, Cu2S, SnO, TiO2, ZnO, ZnS, ZnSe, CdZnS, and CuInSe2 [11]. Among these, CBD CdS deposition is the most studied CBD process due to its important role in fabricating CdTe and CuInSe2 thin-film solar cells.
Surface engineering with Chemically Modified Graphene
Published in Craig E. Banks, Dale A. C. Brownson, 2D MATERIALS, 2018
Paul Sheehan, D. R. Boris, Pratibha Dev, S. C. Hernandez, Woo-Kyung Lee, Shawn Mulvaney, T. L. Reinecke, J. T. Robinson, Stanislav Tsoi, S. G. Walton, Keith Whitener
Chemical bath deposition (CBD) has been widely used to deposit semiconducting thin films since it is scalable, cost-effective, non-destructive, and generally produces high quality films. In general, CBD is less constrained in the choice of substrate than other approaches since it requires only favorable physisorption to promote the deposition of the film. Yet not all substrates are amenable to CBD, and some substrates yield films whose properties could be improved. As an example of the latter, to improve the homogeneity of a cadmium sulfide (CdS) film deposited via CBD, Seo et al. coated glass with graphene, then treated it with UV-ozone to create defects and oxygen-rich functional groups that promoted the nucleation and growth of the CdS.164 A more pronounced challenge is growing films on substrates, such as hydrophobic polymers, that provide poor adhesion to the deposited film.165, 166 Coating such substrates with graphene chemically modified to enhance binding can overcome these limitations. For instance, Lee et al. examined the use of films of graphene and chemically modified graphene to promote growth of CdS on polyethylene (PE), an otherwise inert substrate for CBD (Fig. 11).167 Both visual inspection and atomic force microscopy show that, without a coating, PE will not support CdS growth. Even with a coating of pristine graphene, little CdS growth is observed. However, robust CdS growth was observed with coatings of chemically modified graphenes, such as fluorinated graphene (FG) or oxygenated graphene (OG). Controlling the extent of the fluorination enabled control over the nucleation and growth of CdS, while patterning the fluorination via e-beam plasma (described in a previous section) produced a patterned CdS film. Several other materials beyond CdS such as ZnO, ZnS, or PbS have been developed suggesting that modification of surfaces with chemically modified graphene is a generic strategy to promote the formation of semiconducting films via CBD.
The chemical process for materials deposition in aqueous solution: a review
Published in Surface Engineering, 2022
A. I. Oliva, I. J. González-Chan, P. E. Várguez, A. I. Trejo-Ramos, A. I. Oliva-Avilés
Chemical bath deposition (CBD) technique is a widely used methodology for the growth of materials in thin film geometry with thicknesses ranging from few nm to several microns. This growing method is one of the simplest, cheapest, and easiest to control and implement. The process can be envisioned as a technique where the product is generated and deposited in the same place (the chemical bath). The prepared materials are very comparable with other synthesis pathways using more complex/expensive techniques in terms of quality, physical properties, and adequate conditions for further applications, especially for the commercial interests. Such a technique has been used for many years, for different aims and for a variety of compounds. Great efforts to elucidate the influence of each of the involved parameters have been developed and spread among the scientific community, from the variation of experimental conditions to theoretical approaches based on physicochemical foundations and experimental observations. This review aims to bring a general overview of the CBD technique, the historic evolution and key findings throughout the years, the effect and influence of the major-importance parameters on the resulting materials and the well-established rules of this specific technique. Authors’ perspectives and critical analysis are highlighted, with the aim of bringing clarity on the next steps, missing areas and gaps on the current knowledge.
Mathematical analysis of one-dimensional lead sulphide crystal structure using molecular graph theory
Published in Molecular Physics, 2022
Yogesh Singh, Sunny Kumar Sharma, Purnima Hazra
The quantum dots and nanoparticles containing lead sulphide have been extensively studied and explored in [15]. In addition, various synthesis techniques are employed for the synthesis of PbS thin films, namely chemical vapour deposition (CVD), RF sputtering, vacuum deposition, microwave heating, plasma chemical technique, SILAR method, electrodeposition, pulse electrodeposition method, sublimation method, atomic layer deposition, solution routes, etc. Out of these methods, solution routes including chemical bath deposition (CBD) are quite effective for a variety of reasons, including low cost, quick and simple, no need for complex instruments, suitability for large-scale deposition on a variety of substrates, and the ability to tune thin-films properties by adjusting and controlling initial chemical composition as well as experimental parameters during deposition [16]. However, the solution route of PbS synthesis involved complex chemical reactions. For example, Slonopas et al. [17] have explained the chemical reaction processes for the synthesis of PbS using CBD method in their respective papers as shown in Table 1.
Temperature dependent electrical and optical properties with higher photosensitivity of Cu2Se absorber thin films for photo voltaic application
Published in Inorganic and Nano-Metal Chemistry, 2021
J. Henry, T. Daniel, V. Balasubramanian, K. Mohanraj, G. Sivakumar
The chemical bath deposition (CBD) is relatively inexpensive and capable of handling large- area fabrication technique. In this technique the material wastage is very minimum and there is no need of handling poisonous gases like H2Se and H2S.[9] A few reports are available elsewhere on electrical properties of the copper selenide thin films by chemical bath deposition method. H. M. Pathan et al.[10] was reported the electrical resistivity of chemically prepared Cu2Se thin films of the order of 10−1 Ω cm. P. P. Hankare et al.[11] have investigated the electrical conductivity of copper selenide thin film and it was found to be of the order of 10−3 (Ω m)−1. V. M. Garcia et al.[7] was observed the direct allowed transition with band gap of 2.1–2.3 eV for the chemically deposited copper selenide thin films. Ping Lu et al.[12] have studied the thermoelectric performance of Cu2Se.