Diketopyrrolopyrrole-Based Semiconducting Polymer for Photovoltaic Device with Photocurrent Response Wavelengths up to 1.1 μm

A highly effective photovoltaic polymer with near-infrared response, poly{N-[1-(2-ethylhexyl)-3-ethyl-hexyl)-3-ethylheptanyl]-dithieno[3,2-b:2',3'-d]pyrrole-3,6-dithien-2-yl-2,5-dibutylpyrrolo[3,4-c]pyrrole-1,4-dione-5',5 ''-diyl} {PDTP-DTDPP(Bu)}, was synthesized. The polymer has high molecular weight, good solubility, and a broad absorption spectrum in the range of 500-1100 nm. Field effect transistor charge mobility of PDTP-DTDPP(Bu) arrived 0.05 cm(2)V(-1)s(-1). Bulk heterojunction type polyrner solar cells based on PDTP-DTDPP(Bu) and PC70BM have broad photocurrent response wavelength range from 300 nm to 1.1 mu m. High short-circuit current (14.87 mA/cm(2)) and power conversion efficiency (2.71%) were achieved, which is a significant advance for efficient photovoltaic polymers that respond to the whole range of the solar spectrum.