Department of Materials Science and Engineering, KAIST Institute for the Nanocentury, Korea Advanced Institute of Science and Technology (KAIST) , Daejeon 34141, Korea.
Department of Chemical and Biomolecular Engineering, KAIST Institute for the Nanocentury , Daejeon 34141, Korea.
J Am Chem Soc. 2016 Dec 21;138(50):16478-16485. doi: 10.1021/jacs.6b10681. Epub 2016 Dec 12.
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.
我们报告了一种硅氧烷封装量子点（QD）膜（QD-silox 膜）的制备，即使在高温高湿条件下，其发光强度也能稳定保持超过 1 个月。QD-silox 膜是通过硅氧烷树脂和 QD 上的配体分子之间的自由基加成反应固化的。我们通过硅烷前体与掺杂在前体溶液中的 QD 的溶胶-凝胶缩合反应来制备 QD-低聚硅氧烷树脂，从而避免了 QD 的配体交换。与其他含 QD 的树脂相比，经过 40 天的储存后，所得的 QD-低聚硅氧烷树脂仍保持光学透明，而其他含 QD 的树脂则变得浑浊，最终形成沉淀物。QD 也在 QD-silox 膜中均匀分散，其光致发光（PL）量子产率（QY）在恶劣条件下几乎保持不变；例如，在 85°C/5%相对湿度（RH）、85°C/85%RH、强酸和强碱环境下 40 天。即使将 QD-silox 膜浸入沸水（100°C）中，其发光性能似乎仍然保持不变。有趣的是，当膜暴露在潮湿环境中时，QD-silox 膜的 PL QY 明显增加，这为修复暗淡的含 QD 膜开辟了一条新的简便途径。鉴于其优异的稳定性，我们预计 QD-silox 膜最适合显示应用，特别是作为 PL 型下转换层。
