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.

Efficient content distribution is one of the emerging applications in vehicular networks. To provide scalable content distribution in vehicular networks, Chord peer-to-peer overlay could be applied. Most P2P protocols, including Chord, are designed for wired-line network, and might perform poorly in mobile networks. Mobile Chord (MChord) is proposed to enhance the P2P performance over vehicular ad hoc network (VANET). In addition, cross-layer design to improve MChord performance in VANET is also investigated. Extensive NS-2 simulations with vehicular mobility traces are conducted to evaluate the P2P overlay performance in VANET. Mobile Chord and its cross-layer design outperforms the original Chord in various aspects, including application layer forwarding steps, query response ratio, correct query response ratio, and application delay.

Chord is a popular structured peer-to-peer (P2P) protocol. To provide P2P application service on vehicular wireless networks, Chord overlay on vehicular ad hoc network (VANET) is applied. Most P2P protocols, including Chord, are designed for wired-line network, and might perform poorly in mobile networks. We propose Mobile Chord (MChord) enhancement to improve the performance of Chord over VANET. These techniques are aggressive table update, overlay table broadcasting, greedy forwarding, and passive bootstrapping. We also take network layer traffic into protocol design consideration to alleviate congestion. Through realistic vehicular mobility simulations on NS-2 platform, we find the proposed Mobile Chord outperforms the original Chord in various aspects such as application layer forwarding steps, query response, correct query response, and application delay.