论文标题
通过J51/N2200混合物中深孔的充电转移
Charge transfer via deep hole in the J51/N2200 blend
论文作者
论文摘要
在最近开发的基于非富烯受体（NFA）的有机太阳能电池（OSC）中，供体和受体部分都可以通过吸收光光子来激发。因此，电子传输和孔传输通道都可能发生在供体/受体界面，用于在基于NFA的OSC中生成自由载体。然而，在许多分子和DNA系统中，最近的研究表明，只有最高占用的分子轨道（HOMOS）和最低的无置分子轨道（LUMOS）的供体和受体分子的CT模型不能合理地解释高电荷转移（CT）效率。 In this work, taking an example of a full-polymer blend consisting of benzodithiophenealt-benzotriazole copolymers (J51) as donor and naphthalene diimide-bithiophene (N2200) as acceptor, in which the ultrafast hole transfer has been recently reported, we investigate its CT process and examine the different roles of various frontier molecular orbitals.通过对量子力学电子结构计算和非绝热动力学模拟的联合研究，我们发现J51和N2200的HOMOS之间的孔转移几乎不可能发生，但是从N2200的HOMO转移到J51的HOMO-1的孔转移更加有效。这指出了深孔通道在CT过程中的潜在重要性，并指出，除HOMOS和LUMOS以外的其他分子轨道（FMO）在内，对于构建了一个可靠的物理模型，用于研究分子光电材料中的CT过程。
In recently developed non-fullerene acceptor (NFA) based organic solar cells (OSCs), both the donor and acceptor parts can be excited by absorbing light photons. Therefore, both electron transfer and hole transfer channels could occur at the donor/acceptor interface for generating free charge carriers in NFA based OSCs. However, in many molecular and DNA systems, recent studies revealed the high charge transfer (CT) efficiency cannot be reasonably explained by a CT model with only highest occupied molecular orbitals (HOMOs) and lowest unoccupied molecular orbitals (LUMOs) of donor and acceptor molecules. In this work, taking an example of a full-polymer blend consisting of benzodithiophenealt-benzotriazole copolymers (J51) as donor and naphthalene diimide-bithiophene (N2200) as acceptor, in which the ultrafast hole transfer has been recently reported, we investigate its CT process and examine the different roles of various frontier molecular orbitals. Through a joint study of quantum mechanics electronic structure calculation and nonadiabatic dynamics simulation, we find the hole transfer between HOMOs of J51 and N2200 can hardly happen but the hole transfer from HOMO of N2200 to HOMO-1 of J51 is much more efficient. This points out the underlying importance of deep hole channel in CT process and indicates that including frontier molecular orbitals (FMOs) other than HOMOs and LUMOs is highly necessary to build a robust physical model for studying CT process in molecular optoelectronic materials.
