Molecular Precursor Method for Fabricating p-Type Cu2O and Metallic Cu Thin Films

Abstract

Functional thin ilms are used in various ields of our life. Many diferent methods are used to fabricate these ilms including physical vapor deposition (PVD) and chemical processes. The chemical processes can be used to manufacture thin ilms in a relatively cheap way, as compared to PVD methods. This chapter summarizes the procedures of the molecular precursor method (MPM), a chemical process, for fabrication of both metal oxide semiconductor Cu 2 O and metallic Cu thin ilms by utilizing Cu(II) complexes in coating solutions. The MPM, recently developed and reported by the present authors, represents a facile procedure for thin ilm fabrication of various metal oxides or phosphates. This method pertinent to the coordination chemistry and materials science including nanoscience and nanotechnology has provided various thin ilms of high quality. The MPM is based on the design of metal complexes in coating solutions with excellent stability, homogeneity, miscibility, coatability, etc., which are practical advantages. The metal oxides and phosphates are useful as the electron and/or ion conductors, semiconductors, dielectric materials, etc. This chapter will describe the principle and recent achievement, mainly on fabricating the p-type Cu 2 O and metallic Cu thin ilms of the MPM.

Structural and Optical Properties of ZnO Thin Films Prepared by Molecular Precursor and Sol–Gel Methods

“…It is, thus, important to explore other facile fabrication methods to overcome some of these challenges, and we, therefore, explored the fabrication of ZnO thin films using the molecular precursor method (MPM), which is a wet chemical process for the preparation of metal oxide thin films [29,30]. MPM, unlike the sol-gel method, is based on the use of metal complexes in coating solutions that are known to have excellent stability, homogeneity, and miscibility, owing to the metal complex anions which have better stability and can be dissolved in volatile solvents by combining them with the appropriate alkylamines [31].…”

“…The molecular precursor method (MPM) was employed successfully in the fabrication of copper oxides [31], as well as homogeneous and crack-free titania thin films [32]. Mashiyama and co-workers [33] reported the successful fabrication via MPM of Mg-Zn-O thin films, which exhibited good properties for applications as near-infrared UV-transparent electrodes for GaN-based UV-light-emitting diodes (LEDs).…”

Highly-Conductive and Well-Adhered Cu Thin Film Fabricated on Quartz Glass by Heat Treatment of a Precursor Film Obtained Via Spray-Coating of an Aqueous Solution Involving Cu(II) Complexes

“…The crystallized thin film fabrication by the MPM is based on the redox reaction of the precursor complexes during heat-treatment of the precursor film [9]. The mechanism leading to the Cu 0 thin film formation from the spin-coated precursor film involving Cu(II) complexes was investigated in our previous studies, by using an ethanol solution [10,30]. In the present study, we used aqueous solutions involving the identical raw materials, [Cu(H 2 edta)] and Cu(II) formate, though the used ratio of the Cu(II) species differs from each other.…”

Photo-Induced Super-hydrophilic Thin Films on Quartz Glass by UV Irradiation of Precursor Films Involving a Ti(IV) Complex at Room Temperature

“…The MPM is focused on the design of metal complex salts, which can dissolve into various solvents and form the corresponding genuine solutions [12]. The precursor solutions involving discrete molecular-weight metal complexes can be applied to various substrates through spin-coating [11,13] and spray-coating [14]. Generally, the coated precursor film that is spread homogenously on a substrate can be converted to metal or metal oxide thin films depending on the heat treatment parameters.…”