Investigation of the photoinduced processes in pure C₆₀ films and in C₆₀ films doped by Ti or Sn was performed by means of sub-100 fs resolution spectrometer. Excitation by 100 fs laser pulses with photon energy above and below the mobility edge revealed that both charged and neutral components appear during the excitation pulse. At both excitation wavelengths electrons and holes are generated by direct optical excitation and not due to singlet-singlet annihilation. Anions are created with a delay of 10^-13 - 10^-11 s in a result of electrons capture by C₆₀ molecules. Compared to the pure fullerene this process is faster for Sn-doped and slower for Ti-doped sample. Oxygen uptake in the film is mainly responsible for the observed characteristic features of the relaxation in Ti-doped C₆₀. For Sn-doped C₆₀ the yield of charge carriers photogeneration is noticeably larger than for pure C₆₀. Non-monotonic relaxation, observed in the former case, is explained by the charge exchange between C₆₀ anion and metal.

Date Published: 15 November 2001
PDF: 11 pages
Proc. SPIE 4605, PECS 2001: Photon Echo and Coherent Spectroscopy, (15 November 2001); doi: 10.1117/12.447961

Published in SPIE Proceedings Vol. 4605:
PECS 2001: Photon Echo and Coherent Spectroscopy
Vitaly V. Samartsev, Editor(s)