Excitons with charge transfer in sncl2-phthalocyanine films
  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. 
Ya.I. Vertsimakha, P.M. Lutsyk
cond-mat.mtrl-sci