ACS Appl Mater Interfaces. 2018 Sep 26;10(38):32413-32419. doi: 10.1021/acsami.8b10321. Epub 2018 Sep 11.
Atomistic nonequilibrium molecular dynamics simulations have been used to model the morphology of small-molecule bulk heterojunction films formed by vapor deposition as used in organic photovoltaics. Films comprising C and 1, 5, 10, and 50 wt % of 1,1-bis[4-bis(4-methylphenyl)aminophenyl]cyclohexane (TAPC) were compared to films of neat C. The simulations suggest that if holes can hop between donor molecules separated by as little as 1.2-1.5 nm, then a TAPC concentration of 5 wt % is sufficient to form a percolating donor network and facilitate charge extraction. The results provide an explanation for why low donor content organic photovoltaics can still have high efficiencies. In addition, the roughness, porosity, and crystallinity of the films were found to decrease with increasing TAPC content.
采用原子非平衡分子动力学模拟的方法，模拟了小分子本体异质结薄膜的形态，该薄膜通过气相沉积的方式形成，应用于有机光伏领域。我们将包含 C 和 1wt%、5wt%、10wt%和 50wt%的 1,1-双[4-双(4-甲基苯基)氨基苯基]环己烷（TAPC）的薄膜与纯 C 的薄膜进行了对比。模拟结果表明，如果空穴可以在相隔仅 1.2-1.5nm 的给体分子之间跳跃，那么 TAPC 的浓度为 5wt%，足以形成一个贯穿的给体网络，从而促进电荷提取。该结果解释了为什么低给体含量的有机光伏器件仍然可以具有高效率。此外，还发现薄膜的粗糙度、孔隙率和结晶度随 TAPC 含量的增加而降低。
