White Luminescence from Solid C ₆₀

Abstract

PACS. 78.47 -Time-resolved optical spectroscopies and other ultrafast optical measurements in condensed matter.

On the fluorescence of crystalline C60 at 1.2 K

“…For films of C6o on various supports commonly a broad fluorescence spectrum has been found with a maximum around 735 nm and more or less pronounced shoulders at longer wavelengths [9][10][11][12][13]. In some cases the fluorescence spectrum revealed an additional band around 705 nm [9,14,15]. A spectrum similar to the latter has been reported for a polycrystalline powder sample of C60 [16].…”

“…lb albeit that the vibronic structure becomes obscured due to strong inhomogeneous broadening in the film compared to the crystal. In some of the reported film spectra an additional band shows up around 705 nm which has no pendant in our crystal spectrum [9,14,15]. This extra fluorescence most probably derives from a C6o-related chemical impurity.…”

Spatially Confined High-Temperature Blackbody Radiation from C60 Films

“…The optical properties of C 60 have been attracting much attention because of its unique, spherical π-conjugated electrons. The photoluminescence of C 60 extending from 1.4 to 1.8 eV is usually weak and dominated by the vibronic couplings with the higher energy levels which have appropriate symmetry. , Under high-intensity laser excitation, on the other hand, some groups reported that C 60 powder or small crystallites emit strong and broad luminescence extending to the near-infrared region. , Although it seems to represent some intriguing, still unknown aspects in the optical properties of C 60 , the phenomenon is not yet well understood mainly because important features such as the entire emission spectrum and spatial distribution remain to be revealed.…”

Electric current induced light emission from C 60

“…This transition is weakly allowed because of vibronic coupling to the higher lying ti, orbitals. The photoluminescence spectrum exhibits a peak at 1.7 eV [6]. This is significantly smaller than the band gap of pure CeO, which is about 2.3 eV.…”