Diketopyrrolopyrrole-Containing Oligothiophene-Fullerene Triads and Their Use in Organic Solar Cells

Abstract

We report the characterization of a series of oligothiophene-diketopyrrolopyrrole-fullerene triads and their use as active materials for solution processed organic solar cells (OSCs). By incorporating the diketopyrrolopyrrole (DPP) core with electron rich oligothiophene units and electron withdrawing fullerene units, multifunctional electronic molecules have been prepared; these molecules show high solubility in common organic solvents, excellent photophysical properties with high extinction coefficients (1 × 10(4) to 1 × 10(5) M(-1) cm(-1)) and broad absorption spectra coverage (250-800 nm), as well as suitable molecular orbital energy levels (HOMO of approximately -5.1 eV, LUMO of approximately -3.7 eV). Solution-processed thin-film organic field effect transistors (OFETs) from these triads revealed good n-type characteristics with electron mobilities up to 1.5 × 10(-3) cm(2) V(-1) s(-1). With these multifunctional triads, single-component OSCs have been fabricated, exhibiting power conversion efficiencies (PCEs) of up to 0.5 % under AM 1.5 G simulated 1 sun solar illumination. Blending these molecules with poly(3-hexylthiophene) (P3HT) afforded bulk heterojunction OSCs with PCEs reaching as high as 2.41%.

Sensitization of fullerenes by covalent attachment of a diketopyrrolopyrrole chromophore

“…35,36 More recently, DPP-containing materials, often based on the 3,6-dithien-2-yl-2,5-dialkylpyrrolo [3,4-c]pyrrole-1,4-dione (DTDPP) segment, have also attracted attention in optoelectronic devices. [37][38][39][40][41][42][43][44][45][46][47][48][49][50][51] In particular, many conjugated copolymers with DPP groups, 37,38,41,42,[46][47][48][49][50][51] as well as DPP-based small molecules, 43,[52][53][54][55] have been used in BHJ solar cells. Some covalently linked systems of DPP derivatives with PCBM have also been reported.…”

“…An attempt has been reported to blend a covalent DPP-sensitized PCBM derivative with a conjugated polymer in a BHJ solar cell. 40 We report here the excited-state dynamics of two new triads of DTDPP covalently linked at the nitrogen positions to a couple of [6,6]-phenyl-C 61 -butyric acid ester (PCB) units through alkyl chains of different lengths (n ¼ 6, n ¼ 11), as shown in Scheme 1 together with the abbreviated names of the compounds. The photophysics of PCB-DTDPPH and PCB-DTDPPU was investigated by steady-state and time-resolved absorption as well as emission spectroscopy.…”

Synthesis, linear and nonlinear optical properties of thermally stable ferrocene-diketopyrrolopyrrole dyads

“…Additionally, owing to their reversible redox behaviour, these chromophores recorded different hyperpolarizability values in each of the two redox states and a high on/off (β on /β off ) ratio. Among the various known acceptors such as thiazole, 32 and benzodiazthiazole, 33 diketopyrrolopyrrole unit [34][35][36] has emerged a promising candidate for optoelectronics 37 and organic photovoltaics 34,38 such as organic light emitting diodes (OLEDs), [39][40][41] organic field effect transistors (OFETs), [42][43][44] organic solar cells (OSCs), [45][46][47] dye sensitized solar cells (DSSCs) [48][49] etc. This sub-unit has two amide groups that make it a strong acceptor, and consequently the energy of the lowest unoccupied molecular orbital (LUMO) of D-A or D-π-A systems, wherein appropriately substituted diketopyrrolopyrrole is used as acceptor, is considerably lowered.…”

Naphthalene-, Anthracene-, and Pyrene-Substituted Fullerene Derivatives as Electron Acceptors in Polymer-based Solar Cells

“…Various modifications to C 60 fullerenes have been studied for improving solubility, controlling the lowest unoccupied molecular orbital (LUMO) energy level, and enhancing the light-harvesting ability. [14][15][16][17][18][19][20][21][22][23][24][25][26][27] PC 61 BM in particular has become one of the most widely used electron acceptors and has been extensively studied because of its good solubility characteristics and the high power conversion efficiencies (PCEs) it exhibits in OPVs devices. Research on PC 61 BM most often involves structural modification of the aromatic phenyl and aliphatic butyric methyl ester moieties.…”