Benzothiadiazole (BTZ)-based dyes incorporating dithieno[3,2-b:2',3'-d]pyrrole (DTP) pi-linker has been synthesized for fabricating efficient dye-sensitized solar cells (DSSCs). A reference dye with ethylenedioxythiophene (EDOT) pi-linker has also been prepared. The introduction of DTP broadens absorption, provides a more planar skeleton, and reduces HOMO and LUMO energy gap. IMVS and EIS measurements are used to investigate interfacial electron transfer processes of device. Dyes incorporating DTP exhibit more effective inhibition of charge recombination and more conducive to electron injection than the reference dye with EDOT. Therefore, much higher efficiency is obtained in device fabricated by DTP-based dyes, and the best performance achieves a power conversion efficiency of 8.14% by using Co-phen based electrolyte. In contrast, device based on the reference dye reaches 5.22% at most. IPCE characterizations and the effect of Co-bpy and I-/I-3(-) redox couple are also discussed. The DTP moiety is a good candidate for the design of BTZ-based sensitizers used in DSSCs. (C) 2016 Elsevier B.V. All rights reserved.