title: Behaviour of one-step spray-coated carbon nanotube supercapacitor in ambient light harvester circuit with printed organic solar cell and electrochromic display.
abstract: A printed energy harvesting and storage circuit powered by ambient office lighting and its use to power a printed display is reported. The autonomous device is composed of three printed electronic components: an organic photovoltaic module, a carbon-nanotubes-only supercapacitor and an electrochromic display element. Components are fabricated from safe and environmentally friendly materials, and have been fabricated using solution processing methods, which translate into low-cost and high-throughput manufacturing. A supercapacitor made of spray-coated carbon nanotube based ink and aqueous NaCl electrolyte was charged using a printed organic photovoltaic module exposed to office lighting conditions. The supercapacitor charging rate, self-discharge rate and display operation were studied in detail. The supercapacitor self-discharge rate was found to depend on the charging rate. The fully charged supercapacitor was used as a power source to run the electrochromic display over 50 times.
authors.affiliation: Tampere University of Technology, Department of Automation Science and Engineering, Tampere, FI-33101, Finland.
authors.forename: Sampo
authors.initials: S
authors.lastname: Tuukkanen
authors.affiliation: VTT Technical Research Centre of Finland, P.O.Box 1100, FI-90570 Oulu, Finland.
authors.forename: Marja
authors.initials: M
authors.lastname: Välimäki
authors.affiliation: Tampere University of Technology, Department of Electronics and Communications Engineering, Tampere, FI-33101, Finland.
authors.forename: Suvi
authors.initials: S
authors.lastname: Lehtimäki
authors.affiliation: Tampere University of Technology, Department of Electronics and Communications Engineering, Tampere, FI-33101, Finland.
authors.forename: Tiina
authors.initials: T
authors.lastname: Vuorinen
authors.affiliation: Tampere University of Technology, Department of Electronics and Communications Engineering, Tampere, FI-33101, Finland.
authors.forename: Donald
authors.initials: D
authors.lastname: Lupo