[60]Fulleropyrrolidines Bearing π-Conjugated Moiety for Polymer Solar Cells: Contribution of the Chromophoric Substituent on C₆₀ to the Photocurrent

Abstract

Two fullerene-terthiophene dyads without hexyl chains (3T-C₆₀) and with hexyl chains (3TH-C₆₀) on the terthiophene substituent are synthesized by 1,3-dipolar cycloaddition of corresponding azomethine ylides to C₆₀. The cyclic voltammetry studies indicate no apparent electronic communication between the terthiophene pendent group and the fulleropyrrolidine core in the ground state. However, a significant florescence quenching is observed for 3T-C₆₀ and 3TH-C₆₀, compared to their fluorescent terthiophene (3T) and 3TH precursors, respectively, suggesting the occurrence of strong intramolecular electron/energy transfers in the photoexcited state. Furthermore, these new fulleropyrrolidine derivatives are applied as electron acceptors to fabricate poly(3-hexylthiophene) (P3HT) based bulk heterojunction solar cells. The incident photon-to-current efficiency (IPCE) value of the P3HT/3T-C₆₀ device is significantly higher than that of the P3HT/PCBM cell in wavelengths of 350-420 nm. This finding provides direct evidence for the contribution of 3T excitons to the photocurrent. Replacing 3T-C₆₀ with 3TH-C₆₀ effectively improves the morphology of the photoactive layer and widens the window of optimal D/A ratios, raising the power conversion efficiency (PCE) from 2.14% to 2.54%. Importantly, these devices exhibit superior stability of PCE against high-temperature aging.

[60]Fullerene‐quinoxaline, benzothiadiazole and benzoselenadiazole based dyads for thermally stable polymer solar cells: anchoring of substituent on fullerene with a poly(3‐hexylthiophene) polymer chain

“…S15). Thus, it is confirmed that the chromophoric groups on C 60 have a contribution in the generation of photocurrent . Even though all the synthesized dyads show better light harvesting abilities than the benchmark acceptor PCBM, the PCE values are still lower than for PCBM.…”

“…Among the dyads, TBST‐C 60 shows a maximum PCE of 2.48% due to the higher J sc and fill factor. Based on our previous report, the chromophoric unit on the C 60 of the acceptor also contributes in the generation of photocurrent . To examine the individual contribution of the P3HT donor and dyad acceptor in the generation of photocurrent, the incident photon to current efficiency (IPCE) of the champion devices of each dyad was measured across the entire visible spectral range, as shown in Fig.…”

Synthesis of Aziridinofullerene-Porphyrin Mediated by Triethyl Phosphite: Physicochemical and Electrochemical Properties

“…Synthesis of donor‐acceptor linked dyads, triads and tetrads have been attracted much focus in the last two decades due to their potential application as photosynthetic antenna, reaction center metal compounds and their photo‐induced energy and electron transfer process . In the construction of donor‐acceptor linked dyads, fullerene‐porphyrin system has been used traditionally.…”

Macrocyclic Dyads Based on C60 and Perylenediimides Connected by Click Chemistry

“…Thus, to develop their potential, the fullerene sphere has to be decorated with versatile electroactive molecules that are able to absorb the solar radiation efficiently and transfer it to the fullerene sphere. [16] PDI derivatives are robust and have high molar extinction coefficients in the visible region as well as high fluorescence emission quantum yields. [17] Furthermore, PDI systems are now known to show a fascinating chemical versatility.…”