INVESTIGATION ON STRUCTURE,SPECTRUM AND LINEAR DICHROISM OF Snpc POLYCRYSTALLINE FILMS

Vacuum sublimed Snpc films with a-form and β-form polycrystalline structures were prepared and characterized by optical absorption spectrum and X-ray diffraction measurements. Films grown on anisotropic substrates were measured for polarization absorption. The partially oriented β-SnPc film was found to possess large linear dichroism and the dichromatic absorption axis rotated over 90 degrees when going from the blue side to the red side of the Q exciton band. A new band near 530 urn was observed which was believed to be an inter-molecular charge-transfer excitation band.