Two novel star-shaped donor–acceptor small molecules, TPA–TBT–CN and TPA–TBT–R, with triphenylamine (TPA) as the core, benzothiadiazole (BT) as the arm, and alkyl cyanoacetate or 3-ethylrhodanine as the end-group are synthesized for application as donor materials in OSCs. The two small molecule films show broad absorption bands from 300 nm to 850 nm, narrow optical band gaps (1.5–1.7 eV), deep HOMO energy levels (−5.0 to −5.1 eV) and moderate hole mobilities. OSCs based on blends of the two donors and PC70BM acceptors exhibit power conversion efficiencies of 1.34% and 1.79%, respectively. Notably, TPA–TBT–R with 3-ethylrhodanine as the end-group displays a broader solar spectral coverage, a lower HOMO level, a higher hole mobility and higher photovoltaic properties. Our results indicate that 3-ethylrhodanine as the acceptor and end-group is a promising linker in constructing donor materials for high efficiency OSCs.
以
三苯胺(
TPA)为核,苯并
噻二唑(BT)为臂,
氰乙酸烷基酯或 3-乙基
罗丹宁为末端基团,合成了两种新型星形供体-受体小分子
TPA-TBT-CN 和
TPA-TBT-R,并将其用作 OSC 中的供体材料。这两种小分子薄膜显示出从 300 纳米到 850 纳米的宽吸收带、窄光带隙(1.5-1.7 eV)、深 HOMO 能级(-5.0 到 -5.1 eV)和适中的空穴迁移率。基于这两种给体和 PC70BM 受体混合物的 OSC 功率转换效率分别为 1.34% 和 1.79%。值得注意的是,以 3-ethylrhodanine 为端基的
TPA-TBT-R 显示出更宽的太阳光谱覆盖范围、更低的 HOMO
水平、更高的空穴迁移率和更高的光伏特性。我们的研究结果表明,3-乙基
罗丹宁作为受体和末端基团是一种很有前途的连接体,可用于构建高效 OSC 的供体材料。