Rationally Designed Energy Transfer in Upconverting Nanoparticles
Rationally Designed Energy Transfer in Upconverting Nanoparticles
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DOI：
10.1002/adma.201500248
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发表时间：
2015-10-14
影响因子：
29.4
通讯作者：
Cohen, Bruce E.
中科院分区：
文献类型：
--
作者：
Chan, Emory M.;Levy, Elizabeth S.;Cohen, Bruce E.
在上转换纳米粒子(UCNPs)的分析和理论建模方面取得了重大进展，开始揭示其能量转移(ET)途径的复杂细节。UCNP将多个近红外光子结合在一起，在近红外或可见光下以更高的能量发射，是合理设计和精确设计光学过程的理想系统。驱动光子上转换的ET路径可以通过改变稀土共掺杂的组合、它们的浓度以及它们在纳米晶体中的空间分布来调节。在这里，综述了复杂的UCNP结构的发展，这种结构将稀土元素分离到异质结构中的多个区域或主体晶格的晶胞内。这些设计指导UCNP中的ET以增强其亮度，最大化所需的发射波长，抑制不希望的电子跃迁，并敏化对不同波长的光的吸收。UCNPs中ET的整体计算模型的发展正在产生具有意想不到的性质的新的纳米晶体设计，例如UCNPs在单分子成像能力下具有特殊的亮度。这些合理的ET工程方法将加速UCNPs的开发，这些UCNPs是为特定的纳米光子应用而量身定做的，这些应用需要高效和定向的能量流动。
Significant advances in the analysis and theoretical modeling of upconverting nanoparticles (UCNPs) are beginning to reveal the complex details of their energy transfer (ET) pathways. UCNPs combine multiple NIR photons to emit at higher energies in the NIR or visible, and are an ideal system for the rational design and precise engineering of optical processes. The ET pathways that drive photon upconversion can be tuned by varying the combination of lanthanide co-dopants, their concentrations, and their spatial distribution within the nanocrystal. Here, recent work is reviewed on the development of complex UCNP architectures that segregate lanthanides across multiple domains in a heterostructure or within the unit cell of the host lattice. These designs direct ET in UCNPs to enhance their brightness, to maximize desired emission wavelengths, to suppress undesirable electronic transitions, and to sensitize absorption of light at different wavelengths. The development of holistic computational models for ET in UCNPs is yielding novel nanocrystal designs with unexpected properties, such as UCNPs with exceptional brightness at single molecule imaging powers. These rational approaches for engineering ET will accelerate the development of UCNPs tailored to specific nanophotonic applications that require the efficient and directed flow of energy.