Self-Assembling Fullerenes for Improved Bulk-Heterojunction Photovoltaic Devices

Abstract

The fullerene adducts 1a and 1b, whose molecular shapes either promote or hinder the formation of 1-D stacks, have been examined for their potential to form 1-D wire-like domains in bulk-heterojunction organic solar cells. The photovoltaic efficiency of solar cells based on blends of the stacking fullerene 1a with regioregular poly(3-hexylthiophene-2,5-diyl) (P3HT) is greatly enhanced compared to nonstacking model fullerene 1b.

Tunable Photochemical/Redox Properties of (Phenylthio)ncorannulenes: Application to a Photovoltaic Device

“…9 For example, compared to 1, a pale yellow material with first reduction at −2.33 eV in acetonitrile, decasubstitution of 1 with thiophenol (SPh) produces a deep red material with the first reduction potential at −1.22 eV, 10 which is similar to the reported value of −1.17 volts for [6,6]-phenyl-C 61 -butyric acid methyl ester (PCBM). Given that many high-performing organic photovoltaic (OPV) devices rely on C 60 and its derivatives to act as electron acceptors, 11 this similarity in electrochemistry between PCBM and decakisphenylmercaptocorannulene motivates a study into the nature of tuning the physical properties (electrochemistry, ultraviolet-visible (UV-Vis) absorption, fluorescence, and phosphorescence) of corannulene by phenylmercapto substitution and the photovoltaic characterization of decakis(phenylthio-)corannulene as an acceptor in an OPV device. Furthermore, the optoelectronic tunability of corannulenes makes them potentially useful as organic light emitting diodes (OLEDs), 12 as organic conductors, 13 or in high density carbon electrodes.…”

Panoramic View of Electrochemical Pseudocapacitor and Organic Solar Cell Research in Molecularly Engineered Energy Materials (MEEM)

“…92 For example, the use of t-butyl phenyl alkyl groups (1a) leads to SCs that strongly prefer to assemble into 1D stacks, as evidenced by the crystal structure shown in Figure 11a. 92,94 In contrast, the use of methyl alkyl groups (either in the para (1d) or meta (1e) positions) produces SCs that have no preference to stack ball-in-cup, as shown by the crystal structure of 1d in Figure 11b. Ethyl (1c) and isopropyl (1b) substituents lead to intermediate behavior in the preference to stack.…”

Open‐Cage Fullerenes as n‐Type Materials in Organic Photovoltaics: Relevance of Frontier Energy Levels, Carrier Mobility and Morphology of Different Sizable Open‐Cage Fullerenes with Power Conversion Efficiency in Devices

“…[22][23][24] Challenges toward higher PCE to the limits of theoretical values are focused on the use of PCBM and its analogues as n-type materials, [ 25,26 ] however, only few have been made to develop new fullerene derviatives for OPV applications. [27][28][29][30][31][32][33][34] Li et al recently show that OPVs integrated with indene-C 60 bisadducts and P3HT exhibit high PCE up to 6.5% through increasing LUMO energy levels of electron acceptors. [35][36][37][38][39][40][41] We envisaged that studies of OPVs have been relied on PCBM -type materials for long terms; thus, developing new n-type materials for achieving higher PCE solar cells remains a relatively unexplored topic.…”