兼具三线态-三线态湮灭上转换与单光子吸收上转换特性的氮杂蒽衍生物发光性能研究  

Study on Properties of Azaanthracene Derivatives With Triplet-Triplet Annihilation Upconversion and One-Photon Hot Band Absorption Upconversion

作　　者：徐磊 朱琳 张春 叶常青[1] 陈硕然 李琳 梁作芹[1] 王筱梅[1] XU Lei;ZHU Lin;ZHANG Chun;YE Chang-qing;CHEN Shuo-ran;LI Lin;LIANG Zuo-qin;WANG Xiao-mei(Research Center for Green Printing Nanophotonic Materials,School of Materials Science and Engineering,Suzhou University of Science and Technology,Suzhou 215009,China)

机构地区：[1]苏州科技大学,绿色印刷纳米光子工程技术研究中心,材料科学与工程学院,江苏苏州215009

出　　处：《光谱学与光谱分析》2022年第6期1761-1768,共8页Spectroscopy and Spectral Analysis

基　　金：国家自然科学基金项目(51873145,51673143);江苏省自然科学基金-优秀青年基金项目(BK20170065);江苏省自然科学基金项目(BK20160358);江苏省高校自然科学研究重大项目(17KJA430016);江苏省“六大人才高峰”项目(XCL-79);江苏省第五期“333工程”项目(BRA2018340);江苏省研究生科研创新项目(KYCX20_2760)资助。

摘　　要：弱光上转换是将低能量光子转换为高能量光子的过程,在三维荧光显微成像、太阳能电池、光催化等领域具有广泛的潜在应用,因而成为有机荧光材料领域的热点课题。目前基于三线态-三线态湮灭机制有机弱光上转换材料(TTA-UC)的研究已较为深入,有关发光机理及应用研究均有较多报道;然而针对另一种有机弱光上转换机理--基于单光子热带吸收的弱光上转换(OPA-UC)的研究目前还较为少见。氮杂蒽衍生物由于具有良好的结构刚性和平面性,高的荧光量子产率,是研究TTA-UC和OPA-UC两种有机上转换发光的理想模型分子结构。通过研究比较三种氮杂蒽衍生物:酚藏花红(PSF)、藏红T(SFT)、亚甲基紫(MTV)各自TTA-UC和OPA-UC的发光性能差异,分析探讨了分子结构对OPA-UC发光性能及TTA-UC敏化效率的构效关系。实验发现酚藏花红和藏红T由于具有较高的荧光量子产率,同时辐射衰减常数较大,其主要衰减过程为辐射衰减;而亚甲基紫具有较高的分子内电荷转移能力(ICT),因而非辐射衰减部分更多。研究三种分子的TTA-UC性能,发现亚甲基紫的三线态能级过低无法进行三线态-三线态能量转移过程,而藏红T由于拥有更高的三线态寿命而具有更高的上转换发光效率(9.69%),是酚藏花红体系(3.16%)的3倍。进一步研究酚藏花红和亚甲基紫的OPA-UC性能差异,发现相同浓度条件(10^(-3)mol·L^(-1))下亚甲基紫(0.12%)的OPA-UC发光效率相较于酚藏花红(0.059%)更高,且随着浓度的升高,亚甲基紫的OPA-UC发光增强效应更大。进一步研究表明,在TTA-UC发光过程中,敏化剂的敏化效率主要受分子三线态寿命以及系间窜跃能力影响,寿命越长,系间窜跃能力越强,敏化效率越高;而在OPA-UC发光过程中,湮灭剂分子的发光学率主要受ICT影响,ICT能力越大,分子发光效率越高。使用氮杂蒽分子廉价易得,对未来高性能TTA-UC和OPA-UC发光分�Upconversion is a phenomenon that converts low-energy photons into high-energy photons.It has a wide range of potential applications in three-dimensional fluorescence microscopy,solar cells,photocatalysis and other fields,and thus has become an attractting topic in the field of organic fluorescent materials.At present,the research about organic low light upconversion materials based on the triplet-triplet annihilation(TTA)mechanism has been investigated in much more depth,and there have been many reesearch reports discussing the TTA mechanism and application;while the research discussing on the other organic upconversion mechanism,the one-photon hot band absorption upconversion(OPA-UC),is still relatively rare.Azaanthracene derivatives are ideal model molecular structures for studying TTA-UC and OPA-UC organic upconversion luminescence due to their good structural rigidity,planarity,and high fluorescence quantum yield.This work compares three azaanthracene derivatives:Phenosafranine(PSF),Safranine T(Safranine T,SFT),Methylene Violet(MTV)and their respective TTA-UC and OPA-UC difference in luminescence performance,analyze and explore the structure-activity relationship of molecular structure to OPA-UC luminescence performance and TTA-UC sensitization efficiency.Experiments have found that phensafranine and safranine T had higher fluorescence quantum yields and a larger radiation attenuation constant.The main attenuation process was radiation attenuation,while methylene violet had a higher intramolecular charge transferability(Intramolecular charge transfer,ICT),so the non-radiation attenuation part was more.It was found that the triplet energy level of methylene violet was too low to carry out the triplet-triplet energy transfer process,and safranine T had a higher triplet lifetime due to its higher triplet lifetime.The upconversion luminous efficiency(9.69%)was 3 times(3.16%)of the phensafranine system.Further studying the OPA-UC performance difference between phensafranine and methylene violet and found that the

关 键 词：弱光上转换 三线态-三线态湮灭上转换 单光子吸收上转换 氮杂蒽衍生物 

分 类 号：O629.34[理学—有机化学]