Ye Changqing, Zhou Liwei, Wang Xiaomei, Liang Zuoqin
Jiangsu Key Laboratory for Environmental Functional Materials, Research Center for Green Printing Nanophotonic Materials, Institute of Chemistry, Biology and Materials Engineering, Suzhou University of Science and Technology, Suzhou, 215009, China.
Phys Chem Chem Phys. 2016 Apr 28;18(16):10818-35. doi: 10.1039/c5cp07296d.
Organic upconversion is a unique process in which low-energy light (usually NIR light) is converted to high-energy light through either the two-photon absorption (TPA) mechanism or the triplet-triplet annihilation (TTA) mechanism. Both TPA upconversion (TPA-UC) and TTA upconversion (TTA-UC) have been actively investigated in recent years due to their intriguing applications in optics, biophotonics, and solar energy utilization. Although they show some similarity (i.e., belonging to the nonlinear two-quantum process and needing focused excitation light), TPA-UC and TTA-UC are very different, such as in mechanism, characteristics involved, molecular design and potential applications. Here, we collectively reviewed these two kinds of upconversion processes and compared their respective characteristics and merits. We also present recent advances made in the areas of TPA- and TTA-UC, the remaining challenges and opportunities, with particular emphasis on molecular engineering of these two active upconversion materials.
有机上转换是一种独特的过程，在该过程中，低能量光（通常为近红外光）通过双光子吸收（TPA）机制或三重态-三重态湮灭（TTA）机制被转换为高能量光。近年来，由于双光子吸收上转换（TPA-UC）和三重态-三重态湮灭上转换（TTA-UC）在光学、生物光子学和太阳能利用等方面的有趣应用，它们都受到了积极的研究。尽管它们表现出一些相似性（即属于非线性双量子过程且需要聚焦激发光），但TPA-UC和TTA-UC有很大不同，例如在机制、涉及的特性、分子设计和潜在应用方面。在此，我们对这两种上转换过程进行了综合综述，并比较了它们各自的特性和优点。我们还介绍了TPA-UC和TTA-UC领域的最新进展、剩余的挑战和机遇，特别强调了这两种活性上转换材料的分子工程。
