Novel indolin-2-one-substituted methanofullerenes bearing long n-alkyl chains: synthesis and application in bulk-heterojunction solar cells

Abstract

SummaryAn easy, high-yield and atom-economic procedure of a C60 fullerene modification using a reaction of fullerene C60 with N-alkylisatins in the presence of tris(diethylamino)phosphine to form novel long-chain alkylindolinone-substituted methanofullerenes (AIMs) is described. Optical absorption, electrochemical properties and solubility of AIMs were studied. Poly(3-hexylthiophene-2,5-diyl) (P3HT)/AIMs solar cells were fabricated and the effect of the AIM alkyl chain length and the P3HT:AIM ratio on the solar cell performance was studied. The power conversion efficiencies of about 2% were measured in the P3HT/AIM devices with 1:0.4 P3HT:AIM weight ratio for the AIMs with hexadecyl and dodecyl substituents. From the optical and AFM data, we suggested that the AIMs, in contrast to [6,6]-phenyl-C61-butyric acid methyl ester (PCBM), do not disturb the P3HT crystalline domains. Moreover, the more soluble AIMs do not show a better miscibility with the P3HT crystalline phase.

Real-Time Tracking of Polymer Crystallization Dynamics in Organic Bulk Heterojunctions by Raman Microscopy

“…The weight-average molecular weight (Mw) was >60,000 kg/mol. Different fullerene-based acceptors were studied (Supplementary Information, 5 SI, Section 1): C60, PC61BM, PC71BM, 1-(3,5-di-tret-butyl-4-hydroxybenzyl)-3-(3cyclopropane [1,9](C60-Ih) [5,6]fullerene-3-yl)-indolin-2-one (HBIM), 40 1-Tetradecyl-3-(3cyclopropane [1,9](C60-Ih) [5,6]fullerene-3-yl)-indolin-2-one (AIM8), 41 and characterization of HBIM, AIM8, and IrC60 were reported elsewhere. [40][41][42] All the materials were used without additional purification.…”

“…Solutions for active layers were prepared by dissolving P3HT and fullerene derivatives together in ortho dichlorobenzene (DCB) at a weight ratio of 1:1 and a total concentration of 20 g/L. This ratio was chosen as optimal or close to optimal for solar cells based on P3HT and the studied fullerene derivatives. ,− For the P3HT:PC 61 BM and P3HT:PC 71 BM blends, chlorobenzene (CB) and chloroform (CF) solvents were also used. The solutions were stirred at a magnetic stirrer for 5 h at 75 °C and then were spin-cast at 900 rpm on a glass substrate.…”

“…The weight-average molecular weight (M w ) was >60 000 kg/mol. Different fullerene-based acceptors were studied (Supporting Information, Section 1): C 60 , PC 61 BM, PC 71 BM, 1-(3,5-ditret-butyl-4-hydroxybenzyl)-3-(3-cyclopropane [1,9]-(C 60 -Ih) [5,6]fullerene-3-yl)-indolin-2-one (HBIM), 40 1-tetradecyl-3-(3-cyclopropane [1,9](C 60 -Ih) [5,6]fullerene-3-yl)-indolin-2-one (AIM8), 41 exohedral metallocomplex (η 2 -C 60 )-IrH(CO)[(+)-2,3-O-isopropylidene-2,3-dihydroxy-1,4-bis-(diphenylphosphino)butane] (IrC 60 ), 42 and [6,6]-diphenyl-C 62 -bis(butyric acid methyl ester) (bisPC 61 BM). 43 C 60 , PC 61 BM, bisPC 61 BM, and PC 71 BM with purity of >99.5%; >99.5%; >99.5%; >99%, respectively, were purchased from Solenne BV.…”

“…HBIM and AIM8 were obtained from the Arbuzov Institute of Organic and Physical Chemistry (Russian Academy of Sciences), whereas IrC 60 was obtained from the Nesmeyanov Institute of Organoelement Compounds (Russian Academy of Sciences). Synthesis and characterization of HBIM, AIM8, and IrC 60 have been reported elsewhere. − All the materials were used without additional purification.…”

“…38 Meanwhile, all investigated fullerene derivatives are miscible with P3HT that might result in the amorphous P3HT:fullerene phase. 38,[40][41][42][43] Above Tg, the amorphous phase gains mobility allowing CC to commence, and the IPC starts to grow. Therefore, the CC temperature range -is determined by the amorphous phase composition, namely on the polymer:fullerene weight ratio 33 and the fullerene derivative type (Table S2).…”