Solution processable broadband transparent mixed metal oxide nanofilm optical coatings via substrate diffusion doping. Issue 47 (17th November 2015)

• Record Type: Journal Article
• Authors: Glynn, Colm; Aureau, Damien; Collins, Gillian; O'Hanlon, Sally; Etcheberry, Arnaud; O'Dwyer, Colm
• Is Part Of: Nanoscale. Volume 7:Issue 47(2015)
• Page Start: 20227
• Page End: 20237
• Publication Date: 2015-11-17
• Subjects: Nanoscience -- Periodicals; Nanotechnology -- Periodicals; 620.505
• DOI: 10.1039/c5nr06184a
• Languages: English
• ISSNs: 2040-3364

Abstract

Abstract : Dip-coating of defect-free films of an oxide from its parent liquid-based precursor can be transformed via substrate diffusion doping to a transparent nanofilm coating that exhibits nearly complete transparency across the UV to near-infrared spectral ranges. Abstract : Devices composed of transparent materials, particularly those utilizing metal oxides, are of significant interest due to increased demand from industry for higher fidelity transparent thin film transistors, photovoltaics and a myriad of other optoelectronic devices and optics that require more cost-effective and simplified processing techniques for functional oxides and coatings. Here, we report a facile solution processed technique for the formation of a transparent thin film through an inter-diffusion process involving substrate dopant species at a range of low annealing temperatures compatible with processing conditions required by many state-of-the-art devices. The inter-diffusion process facilitates the movement of Si, Na and O species from the substrate into the as-deposited vanadium oxide thin film forming a composite fully transparent V0.0352 O0.547 Si0.4078 Na0.01 . Thin film X-ray diffraction and Raman scattering spectroscopy show the crystalline component of the structure to be α-NaVO3 within a glassy matrix. This optical coating exhibits high broadband transparency, exceeding 90–97% absolute transmission across the UV-to-NIR spectral range, while having low roughness and free of surface defects and pinholes. The production of transparent films for advanced optoelectronic devices, optical coatings, and low- or high-k oxides is important for planar or complex shaped optics or surfaces. It provides opportunities for doping metal oxides to ternary, quaternary or other mixed metal oxides on glass, encapsulants or other substrates that facilitate diffusional movement of dopant species.