Beijing National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, PKU-HKU Joint Laboratory in Rare Earth Materials and Bioinorganic Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China.
College of Chemistry and Chemical Engineering, Lanzhou University, Lanzhou 730000, China.
J Am Chem Soc. 2021 Dec 15;143(49):20546-20561. doi: 10.1021/jacs.1c10425. Epub 2021 Dec 4.
Upconversion emissions from lanthanide-doped nanocrystals have sparked extensive research interests in nanophotonics, biomedicine, photovoltaics, photocatalysis, . Rational modulation of upconversion emissions is highly desirable to meet the requirements of specific applications. Among the diverse developed methods, local structure engineering is fundamentally feasible, through which the upconversion emission intensity, selectivity, wavelength shift, and lifetime can be tuned effectively. The underlying mechanism of the local-structure-dependent upconversion emissions lies in the degree of parity hybridization and energy level splitting of lanthanide ions as well as the interionic energy transfer efficiency. Over the past few years, there has been significant progress in local-structure-engineered upconversion emissions. In this Perspective, we first introduce the principles of upconversion emissions and typical characterization methods for local structure. Subsequently, we summarize recent achievements in tuning of upconversion emissions through local structure engineering, including host composition adjustment, external field regulation, and interfacial strain management. Finally, we propose a few perspectives that should tackle the current bottlenecks. This Perspective is expected to deepen the understanding of local-structure-dependent upconversion emissions and arouse adequate attention to the engineering of local structure for desired properties of inorganic nanocrystals.
上转换发光源于镧系掺杂纳米晶体，在纳米光子学、生物医学、光伏、光催化等领域引起了广泛的研究兴趣。为了满足特定应用的需求，对其上转换发光进行合理的调制是非常可取的。在已开发的多种方法中，局部结构工程从根本上是可行的，通过这种方法可以有效地调节上转换发光的强度、选择性、波长位移和寿命。局部结构依赖的上转换发光的潜在机制在于镧系离子的奇偶杂交程度和能级分裂以及离子间能量转移效率。在过去的几年中，在局部结构工程化的上转换发光方面取得了重大进展。在本观点中，我们首先介绍了上转换发光的原理和局部结构的典型表征方法。随后，我们总结了通过局部结构工程来调节上转换发光的最新成果，包括主晶格组成调整、外场调控和界面应变管理。最后，我们提出了几点应该解决当前瓶颈的观点。本观点有望加深对上转换发光的局部结构依赖性的理解，并引起对上转换发光的足够重视，以实现无机纳米晶体所需的性质。
