X-TRAP INFLUENCE ON LUMINESCENCE AND ELECTRIC PROPERTIES OF C-60 SINGLE-CRYSTAL

This paper is devoted to investigation of luminescence and some electr ic properties of C-60 single crystal and their connection with X-traps model. Luminescence properties for C-60 single crystal, the temperatu re dependence of the luminescence spectra and decay kinetics were meas ured for wide range of excitation energies. At low temperatures the em ission spectra with well resolved structure were detected. Opposite to the case of C-60 films, the single crystal shape of the luminescence spectra also change with temperature. This behavior can be described i n terms of X-trap model as proposed in [1]. The luminescence kinetics under 36 eV excitation as a function of temperature was investigated i n nanosecond range. At temperature T < 300 K, the decay curve is non-e xponential and it can be fitted formally by two exponents with charact eristic times in the 1-100 ns range. We suppose the explanation of thi s relaxation behavior requires more particular information about elect ron-hole recombination dynamics which can be affected by X-traps. Foll owing X-traps concept we present preliminary results of thermostimulat ed currents spectroscopy experiments. It reveals the availability of t wo thermorelaxation processes in C-60 single crystal and therefore ind eed the presence at least of two types of traps for charges in this cr ystals.