arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2005.04953physics.chem-phcond-mat.mtrl-sci
收藏

J51/N2200共混物中的电荷转移

Charge transfer via deep hole in the J51/N2200 blend

Xiaoyu Xie, Chunfeng Zhang, Haibo Ma

摘要:

在最近开发的基于非富勒烯受体(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可见光子来激发。因此,在基于NFA的OSC中,电子转移和空穴转移通道都可以发生在供体/受体界面处,用于产生自由载流子。然而,在许多分子和DNA系统中,最近的研究表明,高电荷转移(CT)效率不能合理地解释由CT模型只有最高占据分子轨道(HOMO)和最低未占据分子轨道(LUMO)的供体和受体分子。本文以一种由苯并二噻吩-苯并三唑共聚物(J51)为给体,萘二酰亚胺-联噻吩(N2200)为受体的全聚合物共混物为例,研究了其CT过程,考察了不同前线分子轨道的不同作用.通过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HOMO之间几乎不发生空穴转移,而N2200的HOMO向J51的HOMO-1的空穴转移要有效得多。指出了深空穴通道在CT过程中的重要性,指出了在分子光电子材料中建立一个研究CT过程的物理模型时,除了考虑HOMO和LUMO外,还必须考虑前线分子轨道(FMO).

英文摘要:

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.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑