Modification of molecular transitions in fullerene films under ion impacts

Abstract

The photoluminescence properties of as-deposited and 90 MeV Si ion irradiated fullerene films are reported. The irradiation of fullerene films leads to some enhancement or quenching in molecular transition intensities (photoluminescence intensities) depending on the ion fluence. These effects are explained in terms of lowering in the energy level symmetry resulting from induced chemical disordering. The structural modifications occurring upon irradiation were investigated using Fourier transform infrared and UV-vis spectroscopies

The Study of the Optical Properties of C60 Fullerene in Different Organic Solvents

“…The possible HOMO-LUMO gap of the solid C 60 was obtained at 1.69 eV. This value was 10% to 15% smaller than the band gap energy of the C 60 solution, which was 1.99 eV (this was also in agreement with previous results) [81]. Experimentally, five possible excitation transitions existed, as illustrated in Figure 7 by…”

“…HT modes induced vibronic transition at H u and H g orbitals, and the JT distortion effect possibly occurred to the T 1u orbital [26,82,83]. Note: For a , b , and c , the data were taken from Figures 4 to 6, respectively; For d , the data were estimated using the Hückel calculation [80,81]; (1) to (5) corresponds to the red upward arrows in Figure 7. *JT and HT effects possibly occurred.…”

“…Schematic of the electronic structure of C 60 as calculated by the Hückel model [80,81] and its possible electronic excitation transitions experimentally observed in this study. The electronic excitation and emission transitions were numbered in the bracket as (1) to (5) and (6) to (7), respectively.…”

Highly Crystalline Mesoporous C60 with Ordered Pores: A Class of Nanomaterials for Energy Applications

“…The bonding on the wall structure of the MFC 60 ‐130 was observed by NEXAFS and the results are compared with pure C 60 (Figure A). Pristine C 60 displays four definite peaks at 284.2 (C1), 285.8 (C2), 286.2 (C3), and 288.3 (C4) eV, which represent the transition from 1s to the lowest unoccupied molecular orbitals (LUMO), contributing to the 1s orbital excitation to final states of π* resonant feature . Likewise, the higher energy resonance above 290 eV represents the excitation to final states of photoexcited σ* character .…”

Highly Crystalline Mesoporous C60 with Ordered Pores: A Class of Nanomaterials for Energy Applications

“…Pristine C 60 displays four definite peaks at 284.2 (C1), 285.8 (C2), 286.2 (C3), and 288.3 (C4) eV,w hich represent the transition from 1s to the lowest unoccupied molecular orbitals (LUMO), contributing to the 1s orbital excitation to final states of p*r esonant feature. [29] Likewise, the higher energy resonance above 290 eV represents the excitation to final states of photoexcited s*c haracter. [30] Interestingly,N EXAFS spectrum of MFC 60 -130 shows broader p*r esonance (C1 and C4) peaks with ah uge reduction in the intensity,c onfirming the polymerization of C 60 molecules along the wall structure.Similar result has been also observed for the photopolymerised C 60 polymers with non-porous structure.…”