A1 Journal article (refereed)
Correlated effects of fluorine and hydrogen in fluorinated tin oxide (FTO) transparent electrodes deposited by sputtering at room temperature (2021)
Morán-Pedroso, M., Gago, R., Julin, J., Salas-Colera, E., Jimenez, I., de Andrés, A., & Prieto, C. (2021). Correlated effects of fluorine and hydrogen in fluorinated tin oxide (FTO) transparent electrodes deposited by sputtering at room temperature. Applied Surface Science, 537, Article 147906. https://doi.org/10.1016/j.apsusc.2020.147906
JYU authors or editors
Publication details
All authors or editors: Morán-Pedroso, María; Gago, Raúl; Julin, Jaakko; Salas-Colera, Eduardo; Jimenez, Ignacio; de Andrés, Alicia; Prieto, Carlos
Journal or series: Applied Surface Science
ISSN: 0169-4332
eISSN: 1873-5584
Publication year: 2021
Volume: 537
Article number: 147906
Publisher: Elsevier BV
Publication country: Netherlands
Publication language: English
DOI: https://doi.org/10.1016/j.apsusc.2020.147906
Publication open access: Not open
Publication channel open access:
Abstract
The optical and electrical properties of fluorinated tin oxide (FTO) films deposited at room temperature by sputtering have been investigated varying the fluorine content and the hydrogen atmosphere. The complex behavior of the obtained films is disclosed using a wide set of characterization techniques that reveals the combined effects of these two parameters on the generated defects. These defects control the electrical transport (carrier density, mobility and conductivity), the optical properties (band gap and defects-related absorption and photoluminescence) and finally promote the amorphization of the samples. H2 in the sputtering gas does not modify the H content in the films but induces the partial reduction of tin (from Sn4+ to Sn2+) and the consequent generation of oxygen vacancies with shallow energy levels close to the valence band. A variation of up to four orders of magnitude in electrical conductivity is reported in samples with the appropriate fluorine doping and hydrogen fraction in the sputtering gas, maintaining excellent optical transparency. Optimized room temperature grown electrodes reach sheet resistance ~20 Ω/□ and transparency >90%. This room temperature deposition process enables film preparation on flexible organic substrates, such as polyethylene terephthalate (PET), with identical performance of doubtless interest in flexible and large scale electronics.
Keywords: thin films; optical properties; electric properties
Free keywords: transparent conductive materials; fluorinated tin oxide; room temperature film preparation
Contributing organizations
Ministry reporting: Yes
Reporting Year: 2021
JUFO rating: 1
