Flexible white-light-emitting thin-film CsVO3 devices obtained using cesium vanadate aqueous solution

Abstract V2O5 powder was dissolved in aqueous ammonia solution to prepare an aqueous vanadate solution. CsCO3 was subsequently dissolved in this solution to prepare a CsVO3 precursor solution. Polyethylene glycol (PEG) was added to the resulting solution to increase the viscosity of the solution. The films were dip-coated on borosilicate glass and polyethylene terephthalate (PET) substrates using the precursor solution. The obtained precursor film was heat-treated at 60 °C to obtain crystalline CsVO3 films. The resulting CsVO3 film showed white-light emission in a wide wavelength region with a peak of 508 nm on both substrates. Furthermore, The CsVO3 film prepared on the PET substrate showed white-light emission even when the substrate was bent.