Chem ( IF 19.1 ) Pub Date : 2021-09-23 , DOI: 10.1016/j.chempr.2021.09.001 Hannah C Friedman 1 , Emily D Cosco 1, 2 , Timothy L Atallah 1, 3 , Shang Jia 1 , Ellen M Sletten 1 , Justin R Caram 1
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The rational design of bright near and shortwave infrared (NIR: 700–1,000; SWIR: 1,000–2,000 nm) emitters remains an open question with applications spanning imaging and photonics. Combining experiment and theory, we derive an energy gap quantum yield master equation (EQME), describing the fundamental limits in SWIR quantum yields ( for organic chromophores. Evaluating the photophysics of 21 polymethine NIR/SWIR chromophores to parameterize the EQME, we explain the precipitous decline of past 900 nm through decreasing radiative rates and increasing nonradiative losses via high-frequency vibrations relating to the energy gap. Using the EQME, we develop an energy-gap-independent NIR/SWIR chromophore comparison metric. We show electron-donating character on polymethine heterocycles results in relative increases in radiative efficiency obscured by a simultaneous redshift. Finally, the EQME yields rational chromophore design insights shown by how deuteration (backed by our experimental results) or molecular aggregation increases SWIR .
中文翻译：
根据能隙定律建立发射性有机短波红外发色团的设计原则
明亮的近波和短波红外（NIR：700–1,000；SWIR：1,000–2,000 nm）发射器的合理设计仍然是成像和光子学应用中的一个悬而未决的问题。结合实验和理论，我们推导了能隙量子产率主方程（EQME），描述了短波红外量子产率的基本极限（对于有机发色团。通过评估 21 种聚次甲基近红外/短波红外发色团的光物理学来参数化 EQME，我们解释了通过与能隙相关的高频振动降低辐射率和增加非辐射损耗，超过 900 nm。使用 EQME，我们开发了一种与能隙无关的 NIR/SWIR 发色团比较指标。我们展示了聚次甲基杂环的给电子特性导致辐射效率相对增加，但同时发生的红移却掩盖了这一点。最后，EQME 产生了合理的发色团设计见解，通过氘化（由我们的实验结果支持）或分子聚集如何增加 SWIR 来显示 。
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