Current-Voltage Characteristics, Relaxation Properties, and Photosensitivity of Polythiopentacene Films


  • M.P. Gorishnyi Institute of Physics, Nat. Acad. of Sci. of Ukraine





The hysteresis of dark current-voltage characteristics (JVC) has been observed for the first time for polythiopentacene (PTP) films
1540 nm in thickness in sandwich-like ITO(PTP)Ag cells at room temperature and in the range of applied voltages V from 0 to 10 V. At the negative polarity of the ITO electrode, the dark current density J was found to diminish to a stationary value with the time constants τ1 = 10 s and τ2 = 150 s. If the polarity of this electrode was positive, the current-density reduction with τ1 = 10 s was followed by the current-density increase with τ2 = 150 s. The time dependences of J, the densities of the short circuit current, Jsc, and
photocurrent, Jph, and, hence, the algebraic sum Jsc + Jph were found to be governed by relaxation changes in the magnitudes of near-electrode space charges. The photosensitivity S0 of PTP films at their illumination with monochromatic light with a quantum energy of 1.51 eV (photogeneration in the bulk) turned out five times as high as that, when the light quantum energy was 1.77 eV (photogeneration near the electrode). The near-electrode photogeneration is characterized by the presence of horizontal and linearly increasing sections in the dependence S0(V), which are associated with linear and quadratic, respectively, variations of the sum Jsc + Jph with the changing voltage V. For photogeneration in the bulk, this sum depends linearly on V.


C. Marshalk, Bull. Soc. Chim. France 6, 1122 (1939).

C. Marshalk and C. Stumm, Bull. Soc. Chim. France 15, 418 (1948).

Y. Matsunaga, J. Chem. Phys. 42, 2248 (1965).

E.P. Goodings, D.A. Mitchard, and G. Owen, J. Chem. Phys. Perkin Trans. 1, 1310 (1972).

M.P. Gorishnyi, Ukr. Fiz. Zh. 47, 711 (2002).

M.P. Gorishny, Ukr. Fiz. Zh. 51, 339 (2006).

A.L. Briseno, Q. Miao, M.-M. Ling, C. Reese, H. Meng, Zh. Bao, and F. Wudl, J. Am. Chem. Soc. 128, 15576 (2006).

M.P. Gorishnyi, Ukr. Fiz. Zh. 52, 1154 (2007).

P. Lutsyk and Ya. Vertsimakha, Mol. Cryst. Liq. Cryst. 426, 253 (2005).

A.L. Briseno, S.C.B. Mannsfeld X. Lu, Y. Xiong, S.A. Jenekhe, Zh. Bao, and Y. Xia, Nano Lett. 7, 668 (2007).

V.D. Park, J.Ah. Lim, H.S. Lee, and K. Cho, Materials Today 10, N 3, 46 (2007).

M.P. Gorishnyi, M.V. Kurik, and L. Libera, Ukr. Fiz. Zh. 32, 1013 (1987).

M.P. Gorishnyi and P.A. Kondratenko, Ukr. Fiz. Zh. 34, 839 (1989).

E.A. Silinsh, Organic Molecular Crystals: Their Electronic States (Springer, Berlin, 1980).

V.S. Fomenko, Emission Properties of Materials (Naukova Dumka, Kyiv, 1981) (in Russian).

E.A. Silinsh, M.V. Kurik, and V. Capek, Electronic Processes in Organic Molecular Crystals. Localization and Polarization Phenomena (Zinatne, Riga, 1988) (in Russian).



How to Cite

Gorishnyi М. (2022). Current-Voltage Characteristics, Relaxation Properties, and Photosensitivity of Polythiopentacene Films. Ukrainian Journal of Physics, 56(11), 1203.



Solid matter