An improved genetic algorithm is employed to optimize the structure of (C60)N (N≤25) fullerene clusters with the lowest energy. First, crossover with variable precision, realized by introducing the hamming distance, is developed to provide a faster search mechanism. Second, the bit string mutation and feedback mutation are incorporated to maintain the diversity in the population. The interaction between C60 molecules is described by the Pacheco and Ramalho potential derived from first-principles calculations. We compare the performance of the Improved GA (IGA) with that of the Standard GA (SGA). The numerical and graphical results verify that the proposed approach is faster and more robust than the SGA. The second finite differential of the total energy shows that the (C60)N clusters with N=7, 13, 22 are particularly stable. Performance with the lowest energy is achieved in this work.

The purpose of this work is to synthesize a three-dimension C60 polymer using photo-polymerization method. The used pristine materials were C60 precipitates prepared by a liquid-liquid interfacial precipitation (LLIP) method. The prepared LLIP material was set in the vacuum and was compressed in the anvil with the pressure of 600 MPa or 7 GPa. The 4th harmonics FEL with the wavelength of 500 nm was irradiated with macro-pulses (the pulse width of 20 µs) containing very short micro-pulses (the pulse width of 200 fs). The Raman Ag(2) peak of C60 molecules in the vicinity of 1469 cm-1 becomes broad and shifts to the lower energy region as proceeding of polymerization. Under high pressure and/or FEL irradiation the LLIP crystal revealed the large red-shift and the increment of the half width of the Raman Ag(2) peak. Furthermore the LLIP crystal mixture with iodine revealed the more distinctive red-shift, ca.13cm-1 because of highly packing of C60 molecules. The C60 molecular accession by LLIP process and/or the photo-assisted hole-doping from iodine were promising conditions to promote the photo-polymerization effectively.

We fabricated organic p-n heterojunction, p-i-n heterojunction and all-i-layer photovoltaic cells of a zinc phthalocyanine (ZnPc)/1:1 codeposition (ZnPc:C60)/C60 structure with Al cathode. We investigated the effects of the device structure and the cathode material on the photovoltaic properties. The thickness of the i-layer was changed as 0 nm (= p-n heterojunction), 10 nm (= p-i-n heterojunction) or 50 nm (= all-i-layer) with the total thickness of 50 nm. We also changed cathode materials from Al to low-workfunction Mg:Ag electrode. Photovoltaic properties, i.e., short-circuit current density, fill factor and power conversion efficiency, were strongly influenced by the device structure and cathode material. Finally, the power conversion efficiency showed a maximum (1.5%) with the p-i-n structure and a Mg:Ag cathode under Air Mass 1.5 global solar conditions.

PUE films have been found to exhibit an electrostriction effect. We propose the applying them to a moving device such as an actuator similar to artificial muscles using the electrostriction effect. The actuators are of monomorph type fabricated by PUE film and metal electrodes evaporated at different thickness on the film surfaces. Because these actuators work at a high voltage of more than 1 KV, we controlled the molecular structure of the films by doping C60 or CNT derivatives into PUE so that the actuators could operate under a low voltage. The bends of C60 and CNT-doped actuators were larger than those of non-doped actuators and the working voltage was also low. The force of the actuators increased in proportion to the electric field, and strongly depended on the thickness of the PUE films. Furthermore, in order to clarify the relationship between the stretch of PUE film and the bending mechanism of actuators, we measured the space charge of PUE films using the pulsed electroacoustic method.

Polyurethane elastomer (PUE) films similar to polymer gel materials have been found to exhibit the electrostriction effect. We proposed the application their to a moving device such as an actuator without ionic solvent using the electrostriction effect of PUE. The actuators are of monomorph type fabricated by PUE film and metal electrodes evaporated at different thicknesses on the film surface. Because these actuators work at high voltage more than 1 KV, we controlled the molecular structure of the films by doping C60 derivatives (fullerenol) into PUE so that the actuators could operate under a low voltage. In order to clear the bending mechanism of actuators, we measured the space charge of PUE films using the pulsed electroacoustic method.