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The structure, absorption spectra, and photovoltaic response of tetracene (Tc) thin films 120 and 200 nm in thickness deposited in a vacuum of 6.5 MPa onto different substrates at room temperature have been studied. The photovoltaic response is measured by the method of capacitor cell. It is found that island films are formed on glass and quartz substrates, whereas solid polycrystalline films on copper ones, which is a result of the different interaction energies of Tc molecules with one another and with substrate molecules, molecules of ITO layers, and carbon atoms on the substrate surface. In quasi-amorphous films at a temperature of 4.2 K, excited molecules are deformed stronger as compared to those in polycrystalline films and free molecules at 300 K. The photo-emf f at the front (illuminated) free surfaces of Tc films is negative in the spectral interval of 1.637-3.258 eV, which testifies to the hole photoconductivity in the films. The photo-emf r at the rear surface of 120-nm Tc films (illumination through the ITO electrode, which directly contacted with the Tc film) changed its sign in the spectral intervals of 2.193-2.494 and 2.927-3.153 eV as the oxygen concentration in the measuring cell decreased, which testifies to a change of the energy band bending in the Tc films near their rear and front (free) surfaces. K e y w o r d s: tetracene thin films, Al-Tc-Au heterostructures, photovoltaic response.

The optical and photoelectrical properties of heterostructures (HS) SnO 2 ТTTC 60 Ag are investigated. The additional absorption of HS ТTT and C 60 is revealed in comparison with those for their components, which testifies to the formation of complexes between the ТTT and C 60 molecules near the ТTT-C 60 interface. Currentvoltage characteristics (J-V) of a dark current is symmetric, as well as corresponds to the Ohm law for the voltages of 0 to 0.4 V. In the voltage range of 0.4 to 1.0 V, the branch of J-V at the positive polarity (I +) goes above that at the negative polarity (I −) at a SnO 2electrode. Thus, in the double logarithmic scale, I + and I − are described by direct lines with the angular factors 1.77 and 1.37, accordingly, and exponents in the half-logarithmic coordinates (log I−U). The open-circuit voltage V oc has a positive polarity at the SnO 2electrode irrespective of the illumination direction of a sample. Photovoltage is caused by antiblocking bends of bands for holes and electrons near the SnO 2-and Ag-electrodes of ТTT and C 60 films, accordingly. The dark effective specific resistance of the HS SnO 2 ТTTC 60 Ag is equal to 5•10 7 Ohm•cm.

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