Abstract Rare earth doped upconversion nanocrystals (RE-UCNCs) have attracted extensive interests owing to their unique physical properties and great potential applications in bio-application, photonic and photoelectric devices etc. Although UCNCs open doors to a wide range of new opportunities, they are confronting with some difficulties and one of the fatal problems is their low upconvsersion luminescent strength/efficiency. To date, various methods have been explored to solving this significant issue. Totally to say, the methods can be classified into two aspects, the traditional size, structure, surface and crystal field controls of the UCNCs, and the novel local electromagnetic field modulation surrounding the UCNCs. The local electromagnetic field modulation on UCNCs is a powerful strategy to enhance the strength/efficiency of UCNCs, reporting enhancement from several times up to four orders in short times. The timely and concise summary on the previous literatures is significant for more rapid and formulated development of this field. This review is aimed at offering a comprehensive framework for metal/semiconductor plasmon-induced and photonic crystal effect induced upconversion enhancement. Differing from the other review articles, we first introduced the generation principle of localized electromagnetic field in metal/semiconductor nanostructure/photonic crystals, and their general interaction rules with various emitters. Then, we summed up the recent published works on the local field modulation-induced upconversion enhancement, on emphasis we did our best to discover the generality of obtaining highly improved photoluminescence for any emitters and the personality of realizing highly improved upconversion enhancement. We further prospected the future development in this attractive field based on the previous theoretical and experimental results and the requirement of application. The marriage of upconversion with nanophotonic could explore a novel frontier in photonics that potentially spawn many exciting new fields.

中文翻译：

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局部电磁场上变频操纵

摘要 稀土掺杂上转换纳米晶体（RE-UCNCs）由于其独特的物理性质和在生物应用、光子和光电器件等方面的巨大潜在应用而引起了广泛的关注。面临一些困难和致命问题之一是它们的上转换发光强度/效率低。迄今为止，已经探索了各种方法来解决这个重要问题。总的来说，这些方法可以分为两个方面，UCNCs的传统尺寸、结构、表面和晶体场控制，以及围绕UCNCs的新型局部电磁场调制。UCNC 上的局部电磁场调制是增强 UCNC 强度/效率的有力策略，报告增强在短时间内从几次增加到四个订单。对以往文献及时、简明的总结，对于该领域更快速、更规范的发展具有重要意义。本综述旨在为金属/半导体等离子体诱导和光子晶体效应诱导上转换增强提供一个综合框架。与其他评论文章不同，我们首先介绍了金属/半导体纳米结构/光子晶体中局域电磁场的产生原理，以及它们与各种发射体的一般相互作用规则。然后，我们总结了最近发表的关于局部场调制诱导上转换增强的工作，为了强调，我们尽最大努力发现了为任何发射器获得高度改进的光致发光的一般性以及实现高度改进的上转换增强的特性。我们根据之前的理论和实验结果以及应用需求，进一步展望了这一有吸引力的领域的未来发展。上转换与纳米光子的结合可以探索光子学的新前沿，可能会产生许多令人兴奋的新领域。