Search

Two kinds of small molecular dyads (SMDs) based on trithiophene-benzodithiophene-rhodanine (DR3TBDT) main backbone and PBI termini, named SMD2-C6 and SMD2-C12, were designed with different lengths of alkyl linkers (C 6 H 12 and C 12 H 24). The length effect of alkyl linkers on the photovoltaic performance of the two SMDs have been systematically studied. The results show that the length of alkyl linkers can simutaneously tune the energy levels and phase separation in molecular dyad thin films. As a result, a power conversion efficiency of 1.33% was obtained for SMD2-C12 based single-component organic solar cells (SCOSCs), showing higher open-circuit voltage, short-circuit current density, and fill factor than those of SMD2-C6 based devices. Our findings provide a strategy for designing new SMDs and reveal the importance of alkyl linkers' length on the morphology of SMDs toward improved SCOSC performance. Small molecular dyads based on DR3TBDT backbone and PBI end groups with varying alkyl linker lengths have been developed for application in single-component organic solar cells. [Display omitted] • Two molecular dyads based on a donor backbone and perylene bisimides end groups were developed. • Different alkyl linkers as C 6 H 12 and C 12 H 24 were introduced. • Longer alkyl linkers were found to improve the nanophase separation and provided higher efficiency in single-component organic solar cells. [ABSTRACT FROM AUTHOR]