Indacenodithiophene (IDT)‐based high‐efficiency photovoltaics have received increasing attention recently. This paper reports a density functional theory investigation of the electronic and optical properties of three IDT‐based organic dyes together with the dye/(TiO₂)₄₆ interface. In order to enhance the photoelectric properties of IDT dyes, this paper considers two methods for the structure modification of the experimentally reported dye DPInDT (J. Org. Chem. 2011, 76, 8977): the extension of the conjugation length by dithienothiophene as well as the heteroatom substitution of the bridging atoms by electron‐rich nitrogen atoms. Our calculations show that both methods obviously affect the distributions of the molecular orbitals and notably red shift the absorption peaks of around 20 nm, with the former method demonstrating enhanced light harvesting efficiency. The structure modifications proposed also enhance the emission spectrum properties for IDT‐based organic dyes. The calculated ultrafast injection time of electrons from the excited state of IDT dyes to the (TiO₂)₄₆ belongs to the femtosecond order of magnitude, and is ideal for efficient photoelectric conversion process in dye‐sensitized solar cells (DSSCs) applications. The IDT dyes designed in this paper have good electronic and spectroscopic properties. This study is expected to provide useful guidance for the development of novel IDT dyes for applications in DSSCs.

中文翻译：

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用于高效染料敏化太阳能电池的新型基于茚并二噻吩的有机染料的分子设计

最近，基于茚并二噻吩（IDT）的高效光伏技术受到越来越多的关注。本文报道了三种基于IDT的有机染料以及染料/（TiO ₂）₄₆的电子和光学性质的密度泛函理论研究。界面。为了增强IDT染料的光电性能，本文考虑了两种方法对实验报道的染料DPInDT进行结构修饰（J. Org。Chem。2011，76，8977）：二硫代噻吩还可以延长共轭长度。作为桥接原子被富电子氮原子的杂原子取代。我们的计算表明，这两种方法都明显影响分子轨道的分布，并且显着地红移了约20 nm的吸收峰，而前一种方法证明了提高的光收集效率。提出的结构修改还增强了基于IDT的有机染料的发射光谱特性。计算出的电子从IDT染料的激发态到（TiO ₂）的超快注入时间₄₆属于飞秒量级，是染料敏化太阳能电池（DSSC）应用中有效光电转换过程的理想选择。本文设计的IDT染料具有良好的电子和光谱性质。预期该研究将为开发用于DSSC的新型IDT染料提供有用的指导。