title: Star-shaped and linear π-conjugated oligomers consisting of a tetrathienoanthracene core and multiple diketopyrrolopyrrole arms for organic solar cells.
abstract: Solution-processable star-shaped and linear π-conjugated oligomers consisting of an electron-donating tetrathienoanthracene (TTA) core and electron-accepting diketopyrrolopyrrole (DPP) arms, namely, TTA-DPP4 and TTA-DPP2, were designed and synthesized. Based on density functional theory calculations, the star-shaped TTA-DPP4 has a larger oscillator strength than the linear TTA-DPP2, and consequently, better photoabsorption property over a wide range of visible wavelengths. The photovoltaic properties of organic solar cells based on TTA-DPP4 and TTA-DPP2 with a fullerene derivative were evaluated by varying the thickness of the bulk heterojunction active layer. As a result of the enhanced visible absorption properties of the star-shaped π-conjugated structure, better photovoltaic performances were obtained with relatively thin active layers (40-60 nm).
authors: International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan; INAMORI Frontier Research Center (IFRC), Kyushu University.
authors: Hideaki
authors: H
authors: Komiyama
authors: International Institute for Carbon Neutral Energy Research (WPI-I2CNER), Kyushu University, 744 Motooka, Nishi-ku, Fukuoka 819-0395, Japan; Center for Organic Photonics and Electronics Research (OPERA), Kyushu University.
authors: Chihaya
authors: C
authors: Adachi
authors: INAMORI Frontier Research Center (IFRC), Kyushu University.
authors: Takuma
authors: T
authors: Yasuda
keywords: bulk heterojunction; diketopyrrolopyrrole; organic solar cells; star-shaped oligomers; tetrathienoanthracene