  The absorption, modulated photoreflectance, and photovoltage spectra of
dichlorotin phthalocyanine (SnCl2Pc) films have been measured. These films are
thermally deposited in vacuum at different substrate temperatures. The energies
of charge-transfer-states (CT-states) in SnCl2Pc films (1.35, 1.52, and 2.05
eV) and the diffusion length of Frenkel excitons (130+/-30 nm) have been
determined. The photosensitivity of SnCl2Pc films is comparable to that of
n-type perylene derivative (MPP) layers and by several times (~ 5) more than
the photosensitivity of thermally deposited n-type C60 films.
