Shariatinia Zahra, Sarmalek Seyed-Iman
Department of Chemistry, Amirkabir University of Technology (Tehran Polytechnic), P.O.Box:15875-4413, Tehran, Iran.
Sci Rep. 2022 Aug 17;12(1):13954. doi: 10.1038/s41598-022-18469-1.
Several butterfly-shaped materials composed of dibenzo[b,d]thiophene (DBT) and dibenzo-dithiophene (DBT5) cores were designed as hole transporting materials (HTMs) and their properties were studied by density functional theory (DFT) computations for usage in mesoscopic n-i-p perovskite solar cells (PSCs). To choose suitable HTMs, it was displayed that both of lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) energies of molecules were located higher than those of CHNHPbI (MAPbI) perovskite as they were able to transfer holes from the MAPbI toward Ag cathode. Negative solvation energy (ΔE) values for all HTMs (within the range of - 5.185 to - 18.140 kcal/mol) revealed their high solubility and stability within CHCl solvent. The DBT5-COMe demonstrated the lowest values of band gap (E = 3.544) and hardness (η = 1.772 eV) (the greatest chemical activity) and DBT5-CF displayed the biggest η = 1.953 eV (maximum stability) that were predominantly valuable for effective HTMs. All HTMs presented appropriately high LHEs from 0.8793 to 0.9406. In addition, the DBT5 and DBT5-SH depicted the lowest exciton binding energy (E) values of 0.881 and 0.880 eV which confirmed they could produce satisfactory results for the PSCs assembled using these materials. The DBT5-SH and DBT5-H had maximum hole mobility (μ) values of 6.031 × 10 and 1.140 × 10 which were greater than those measured for the reference DBT5 molecule (μ = 3.984 × 10 cm/V/s) and about 10 and 100 times superior to the calculated and experimental μ values for well-known Spiro-OMeTAD. The DBT5-COOH illustrated the biggest open circuit voltage (V), fill factor (FF) and power conversion efficiency (PCE) values of 1.166 eV, 0.896 and 23.707%, respectively, establishing it could be as the best HTM candidate for high performance PSCs.
设计了几种由二苯并[b,d]噻吩（DBT）和二苯并二噻吩（DBT5）核组成的蝶形材料作为空穴传输材料（HTM），并通过密度泛函理论（DFT）计算研究了它们在介观n-i-p钙钛矿太阳能电池（PSC）中的性能。为了选择合适的HTM，结果表明，分子的最低未占据分子轨道（LUMO）和最高占据分子轨道（HOMO）能量均高于CHNHPbI（MAPbI）钙钛矿，因为它们能够将空穴从MAPbI转移到Ag阴极。所有HTM的负溶剂化能（ΔE）值（在-5.185至-18.140 kcal/mol范围内）表明它们在CHCl溶剂中具有高溶解性和稳定性。DBT5-COMe的带隙（E = 3.544）和硬度（η = 1.772 eV）值最低（化学活性最大），DBT5-CF的η值最大，为1.953 eV（稳定性最高），这对有效的HTM非常重要。所有HTM的光热转换效率（LHE）均适度较高，范围为0.8793至0.9406。此外，DBT5和DBT5-SH的激子结合能（E）值最低，分别为0.881和0.880 eV，这证实了它们在使用这些材料组装的PSC中能够产生令人满意的结果。DBT5-SH和DBT5-H的最大空穴迁移率（μ）值分别为6.031×10和1.140×10，大于参考DBT5分子的测量值（μ = 3.984×10 cm/V/s），分别比著名的Spiro-OMeTAD的计算值和实验值高约10倍和100倍。DBT5-COOH的开路电压（V）、填充因子（FF）和功率转换效率（PCE）值最大，分别为1.166 eV、0.896和23.707%，表明它可能是高性能PSC的最佳HTM候选材料。
