Enhanced upconversion of NaYF4:Er3+/Yb3+ phosphors prepared via the rapid microwaveassisted hydrothermal route at low temperature: Phase and morphology control

Som S.Das S.Yang C.-Y.Lu C.-H.2019-05-132019-05-13201601469592https://scholars.lib.ntu.edu.tw/handle/123456789/407357Monophasic NaYF4:Er3+/Yb3+ crystals were synthesized via the microwave-assisted hydrothermal route at 180¢XC. Microwave heating during the hydrothermal process substantially reduces the duration of reaction for the formation of cubic-NaYF4:Er3+/Yb3+ nanocrystals from 6 h to 30 min. As the duration of the reaction increases, cubic-NaYF4:Er3+/Yb3+ nanocrystals are transformed to uniform hexagonal-NaYF4:Er3+/Yb3+ microprisms because of the enhanced reaction kinetics. Bright upconverted emission from the NaYF4:Er3+/Yb3+ crystal, obtained by the efficient two-photon excitation, is related to crystal structure and morphology. The hexagonal microprisms exhibit better upconversion and are employed in security applications. ? 2016 Optical Society of America.[SDGs]SDG7Enhanced upconversion of NaYF4:Er3+/Yb3+ phosphors prepared via the rapid microwaveassisted hydrothermal route at low temperature: Phase and morphology controljournal article10.1364/OL.41.0004642-s2.0-84962163345https://www.scopus.com/inward/record.uri?eid=2-s2.0-84962163345&doi=10.1364%2fOL.41.000464&partnerID=40&md5=36a10cc017b0a1f6be4a2b30e92c15f0