We report fabrication and electrical characterization of the organic-inorganic semiconductor diode structures formed by evaporating thin films of three novel low molecular mass organic compounds on n-type Si substrates. The organic compounds containing carbazole and triphenylamine structural units, namely: 9,9 -bis(4-butylphenyl)-3,3 --bicarbazolyl (BPBC), 4-(1H-perimidin-2-yl)-N ,N -diphenylbenzenamine (PER) and 9,9 -diethyl-3,3 -bicarbazolyl (EBC) have been synthesized. The current-voltage characteristics of the Au/(BPBC, EBC, PER)/n-Si diode structures measured at T = 295 K revealed rectifying behavior with a potential barrier height values of 0.71 eV, 0.73 eV, 0.76 eV, respectively.