光子晶体调控弱光上转换材料制备与增强固态上转换发光研究

项目名称： 光子晶体调控弱光上转换材料制备与增强固态上转换发光研究

项目编号： No.51303122

项目类型： 青年科学基金项目

立项/批准年度： 2014

项目学科： 一般工业技术

项目作者： 叶常青

作者单位： 苏州科技学院

项目金额： 25万元

中文摘要： 长波激发短波发射频率上转换在太阳能电池、光催化降解和生物成像等领域显现诱人应用前景。基于三线态-三线态湮灭机制上转换（TTA-UC）由于所需激发光能量接近太阳光强度、溶液态上转换效率较高，最具研究价值。然而空气中氧能完全猝灭上转换体系三线态；光敏剂和湮灭剂在固态中扩散和碰撞受限导致固态上转换效率极低。 本项目将光敏剂-湮灭剂以非共轭键连接以增强两者之间能量传递；用高分子包覆光敏剂与湮灭剂，制备单分散纳米微球，突破目前TTA上转换研究受限于绝氧和溶液条件。通用自组装构建光子晶体微腔结构；利用光子晶体独特的光子禁带、光子局域和带边慢光子效应，提高光敏剂的吸收效率、光敏剂与湮灭剂之间三线态能量转换效率和湮灭剂分子之间三线态湮灭效率；通过研究光子晶体微腔内上转换过程中的三线态能量转移通道，探讨影响弱光上转换发光效率的因素，实现高效固态上转换发光，为弱光上转换技术向固态器件应用探索一条新途径。

中文关键词： 固态；上转换；弱光；光子晶体；三线态-三线态湮灭

英文摘要： Upconversion (UC), that is, observation of photon emission, or more generally, population of excited state at higher energy (shorter wavelength) with excitation at lower energy (longer wavelength), has attracted much attention due to its potential applications. Triplet-triplet annihilation (TTA) is a promising upconversion approach due to its low excitation power density (solar light is sufficient), high upconversion quantum yield in solution state( > 30%), readily tunable excitation/emission wavelength. However, the developments of TTA-UC are facing some big challenges, for example the fabrication of devices suitable for practical applications appears far away, since it is quite difficult to obtain high-efficiency solid-state systems. The largest up-conversion efficiency reported up to now for a rigid polymeric matrix is less than 1%. Moreover，the up-conversion system should be completely shielded from the external environment, because oxygen is a quencher of all of the metastable triplets involved in the up-conversion process. In this project , we propose an original approach to incorporate bi-component organic systems for high-efficiency upconversion in the solid state. The photonic crystals (PCs) structure is firstly introduced in enhancing the efficiency of TTA-UC in the solid state. TTA-UC core-shell micro

英文关键词： in solid state；upconversion ；low intensity of excitation；photonic crystal；triplet-triplet annihilation