共價有機框架白光發光二極體的共軛和聚合定向設計
作者:
小柯機器人發布時間:2021/1/7 13:16:08
馬凱特大學Jier Huang團隊開發了一種共價有機框架白光發光二極體的共軛和聚合定向設計策略。 相關研究成果於2021年1月4日發表於國際一流學術期刊《美國化學會志》。
二維共價有機框架(COFs)由於其結構的多樣性而成為一類很有前途的有機發光材料,它允許系統地調節有機構建單元以優化發光性能。然而,設計策略與決定其光物理性質的關鍵結構參數的基本理解之間存在巨大的知識鴻溝。
在該項工作中,研究人員報告了兩種高發射性質的sp2-C-COFs,並研究了其結構(共軛和聚集)與光吸收/發射、電荷轉移(CT)和激子動力學之間的直接關係,這些特性決定了它們作為發光材料的功能。研究人員證明,只需在LED條上塗覆COFs或將兩種COFs混合即可獲得白光。時間分辨吸收和發射光譜以及計算預測的組合研究表明,偶極矩的平面性、共軛性和方向性以及層間聚集不僅決定了COFs的光捕獲能力,而且還控制著激子弛豫路徑和光致發光量子產率。
附:英文原文
Title: Conjugation- and Aggregation-Directed Design of Covalent Organic Frameworks as White-Light-Emitting Diodes
Author: Sizhuo Yang, Daniel Streater, Christian Fiankor, Jian Zhang, Jier Huang
Issue&Volume: January 4, 2021
Abstract: 2D covalent organic frameworks (COFs) have emerged as a promising class of organic luminescent materials due to their structural diversity, which allows the systematic tuning of organic building blocks to optimize emitting properties. However, a significant knowledge gap exists between the design strategy and the fundamental understanding of the key structural parameters that determine their photophysical properties. In this work, we report two highly emissive sp2-C-COFs and the direct correlation of the structure (conjugation and aggregation) with their light absorption/emission, charge transfer (CT), and exciton dynamics, the key properties that determine their function as luminescent materials. We show that white light can be obtained by simply coating COFs on an LED strip or mixing the two COFs. Using the combination of time-resolved absorption and emission spectroscopy as well as computational prediction, we show that the planarity, conjugation, orientation of the dipole moment, and interlayer aggregation not only determine the light-harvesting ability of COFs but also control the exciton relaxation pathway and photoluminescent quantum yield.
DOI: 10.1021/jacs.0c11719
Source: https://pubs.acs.org/doi/10.1021/jacs.0c11719