title: Quantum Dot/Siloxane Composite Film Exceptionally Stable against Oxidation under Heat and Moisture.
abstract: We report on the fabrication of a siloxane-encapsulated quantum dot (QD) film (QD-silox film), which exhibits stable emission intensity for over 1 month even at elevated temperature and humidity. QD-silox films are solidified via free radical addition reaction between oligosiloxane resin and ligand molecules on QDs. We prepare the QD-oligosiloxane resin by sol-gel condensation reaction of silane precursors with QDs blended in the precursor solution, forgoing ligand-exchange of QDs. The resulting QD-oligosiloxane resin remains optically clear after 40 days of storage, in contrast to other QD-containing resins which turn turbid and ultimately form sediments. QDs also disperse uniformly in the QD-silox film, whose photoluminescence (PL) quantum yield (QY) remains nearly unaltered under harsh conditions; for example, 85 °C/5% relative humidity (RH), 85 °C/85% RH, strongly acidic, and strongly basic environments for 40 days. The QD-silox film appears to remain equally emissive even after being immersed into boiling water (100 °C). Interestingly, the PL QY of the QD-silox film noticeably increases when the film is exposed to a moist environment, which opens a new, facile avenue to curing dimmed QD-containing films. Given its excellent stability, we envision that the QD-silox film is best suited in display applications, particularly as a PL-type down-conversion layer.
authors.affiliation: Department of Materials Science and Engineering, KAIST Institute for the Nanocentury, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141, Korea.
authors.forename: Hwea Yoon
authors.identifier: 0000-0002-1451-7591
authors.initials: HY
authors.lastname: Kim
authors.affiliation: Department of Chemical and Biomolecular Engineering, KAIST Institute for the Nanocentury , Daejeon 34141, Korea.
authors.forename: Da-Eun
authors.initials: DE
authors.lastname: Yoon
authors.affiliation: Department of Materials Science and Engineering, KAIST Institute for the Nanocentury, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141, Korea.
authors.forename: Junho
authors.initials: J
authors.lastname: Jang
authors.affiliation: Department of Materials Science and Engineering, KAIST Institute for the Nanocentury, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141, Korea.
authors.forename: Daewon
authors.initials: D
authors.lastname: Lee
authors.affiliation: Department of Materials Science and Engineering, KAIST Institute for the Nanocentury, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141, Korea.
authors.forename: Gwang-Mun
authors.initials: GM
authors.lastname: Choi
authors.affiliation: Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS) , Daejeon 34141, Korea.
authors.forename: Joon Ha
authors.identifier: 0000-0001-8877-9917
authors.initials: JH
authors.lastname: Chang
authors.affiliation: Center for Nanomaterials and Chemical Reactions, Institute for Basic Science (IBS) , Daejeon 34141, Korea.
authors.forename: Jeong Yong
authors.initials: JY
authors.lastname: Lee
authors.affiliation: Department of Chemical and Biomolecular Engineering, KAIST Institute for the Nanocentury , Daejeon 34141, Korea.
authors.forename: Doh C
authors.identifier: 0000-0002-3489-6189
authors.initials: DC
authors.lastname: Lee
authors.affiliation: Department of Materials Science and Engineering, KAIST Institute for the Nanocentury, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141, Korea.
authors.forename: Byeong-Soo
authors.identifier: 0000-0001-9424-1830
authors.initials: BS
authors.lastname: Bae