Rahman Ata Ur, Khan Muhammad Bilal, Yaseen Muhammad, Rahman Gul
Institute of Chemical Sciences, University of Peshawar, Peshawar 25120, Pakistan.
ACS Omega. 2021 Oct 18;6(42):27640-27653. doi: 10.1021/acsomega.1c02121. eCollection 2021 Oct 26.
Structure engineering of boron dipyrromethene (BODIPY) organic dye, to increase its light-harvesting efficiency in dye-sensitized solar cells, has been the subject of rigorous research recently. Herein, we report on the rational designing of BODIPY-carbazole (D-π-A-A) dyads using density functional theory (DFT). The structure of BODIPY-carbazole was first modified by substituting an electron-donating -N(CH) group at the electron-rich carbazole moiety, and two electron-accepting -COOH groups at the BODIPY core. The DFT calculations showed a significant lowering of the band gap from 2.9 eV (pristine BODIPY-carbazole dyad) to 1.87 eV (modified BODIPY-carbazole dyad). Further modification was demonstrated by the incorporation of heterocyclic rings such as thiophene (denoted as D1T), furan (D1F), and phosphole (D1P) into BODIPY-carbazole moiety, which red-shifted the light absorption spectra and consequently improved the light-harvesting efficiency of the dyes. The interactions at the dye/semiconductor interface were studied by employing their bridged-bidentate adsorption models over the titanium dioxide (TiO) nanocluster. Results suggested that the electrons can be efficiently injected from the lowest unoccupied molecular orbital (LUMO) of dyes into the conduction band of TiO. Among the three dyads, D1P exhibited superior photovoltaic performance with a maximum power conversion efficiency of 13.50%, a short-circuit current density ( ) of 27.2 mA·cm, and an open-circuit voltage ( ) of 731 mV. The structurally configured new D1P dye can be used as a potential alternative photosensitizer for high-performance dye-sensitized solar cells.
硼二吡咯亚甲基（BODIPY）有机染料的结构工程旨在提高其在染料敏化太阳能电池中的光捕获效率，这是近年来严格研究的主题。在此，我们报告了使用密度泛函理论（DFT）对BODIPY-咔唑（D-π-A-A）二元体系的合理设计。首先通过在富电子咔唑部分取代供电子的-N(CH)基团，并在BODIPY核心引入两个吸电子的-COOH基团来修饰BODIPY-咔唑的结构。DFT计算表明，带隙从2.9 eV（原始BODIPY-咔唑二元体系）显著降低至1.87 eV（修饰后的BODIPY-咔唑二元体系）。通过将噻吩（记为D1T）、呋喃（D1F）和磷杂环戊二烯（D1P）等杂环引入BODIPY-咔唑部分进行进一步修饰，这使光吸收光谱发生红移，从而提高了染料的光捕获效率。通过在二氧化钛（TiO₂）纳米团簇上采用桥连双齿吸附模型研究了染料/半导体界面处的相互作用。结果表明，电子可以从染料的最低未占据分子轨道（LUMO）有效地注入到TiO₂的导带中。在这三种二元体系中，D1P表现出优异的光伏性能，最大功率转换效率为13.50%，短路电流密度（Jsc）为27.2 mA·cm⁻²，开路电压（Voc）为731 mV。结构配置的新型D1P染料可作为高性能染料敏化太阳能电池的潜在替代光敏剂。
