title: Theoretical investigations on enhancing the performance of terminally diketopyrrolopyrrole-based small-molecular donors in organic solar cell applications.
abstract: Diketopyrrolopyrrole (DPP)-based small molecules with acceptor-core-acceptor (A-core-A) type as donor materials have been used successfully in organic solar cells (OSC). In this work, based on the DPP-core-DPP type molecule SM1 consisting of a DPP unit as acceptor and benzene as the core, we replaced the benzene core with more electron-withdrawing groups in SM1 and further designed four new small-molecular donors (SM2-SM5) in order to improve the electrical properties, optical absorption and performance in OSC applications. The calculated results indicate that the designed small-molecular donors SM2-SM5 exhibit better performances in comparison with SM1, such as lower highest occupied molecular orbital (HOMO), narrower energy gap, larger absorption range, better electronic transfer between donor and acceptor and higher hole mobility. Moreover, the decreased HOMO levels and transition energy of small-molecular donors in OSC applications play an important role in the parameters of open-current voltage, fill factor and short-circuit current. Consequently, adjusting the electron-deficient ability of cores in DPP-core-DPP type small-molecular donors is an efficient approach that can be used to obtain high-efficiency DPP-based small-molecular donors for OSC applications. Graphical Abstract The designed small-molecules with good electronic and photophysical properties will act as a promising donor candidate for organic solar cell applications. Moreover, The decreased HOMO levels and transition energy of small-molecular donors in OSC applications play an important role in the parameters of open-current voltage, fill factor and short-circuit current.
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), College of Pharmaceutical Sciences, Southwest University, Ministry of Education, Chongqing, 400715, China.|School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China.
authors.forename: Xiaorui
authors.initials: X
authors.lastname: Liu
authors.affiliation: Key Laboratory of Luminescent and Real-Time Analytical Chemistry (Southwest University), College of Pharmaceutical Sciences, Southwest University, Ministry of Education, Chongqing, 400715, China.
authors.forename: Chengzhi
authors.initials: C
authors.lastname: Huang
authors.affiliation: School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China.
authors.forename: Wei
authors.initials: W
authors.lastname: Shen
authors.affiliation: School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China.
authors.forename: Rongxing
authors.initials: R
authors.lastname: He
authors.affiliation: School of Chemistry and Chemical Engineering, Southwest University, Chongqing, 400715, China. liming@swu.edu.cn.
authors.forename: Ming
authors.initials: M
authors.lastname: Li
mesh_terms: D007659:Ketones / Q000737:chemistry*; D008956:Models, Chemical; D011758:Pyrroles / Q000737:chemistry*; D012993:Solar Energy
chemical_list: D007659:Ketones; D011758:Pyrroles; C000604894:diketopyrrolopyrrole dye
keywords: Charge transfer; Density functional theory; Hole mobility; Organic solar cell; Small-molecular donors