Electroluminescence of fullerene C60-doped poly(methyl methacrylate)

Electroluminescence (EL) of fullerene C60-doped poly(methyl methacrylate) (PMMA) thin film with 10% N,N′-diphenyl-N,N′-di(m-toly)benzidene (TPD) and 10% 2-(4-biphenyl)-5-(4-tert-butylphenyl)-1,3,4-oxadiazole (PBD) is first reported. Their EL spectra range from visible to near infrared with two peaks at around 716 and 810 nm and the EL intensity increases nonlinearly with the concentration of C60. As the ratio of C60/PMMA reaches 15, intense EL with maximum is observed. Secondly, the voltage–current (V–I) characteristics of the devices with C60-doped PMMA films show typical diode behavior. Their threshold voltages decrease with an increase of the concentration of C60. Laser irradiation (wavelength: 488 nm) reduces their EL intensity and has some influence on their EL spectral shape and V–I characteristics.