A study is performed of the photophysical properties of indolo[3,2-b]carbazole-based compounds synthesized earlier. The charge carrier mobility in the space charge-limited current mode and the energy levels of the highest occupied and lowest unoccupied molecular orbitals in the compounds are determined. It is shown that indolo[3,2-b]carbazole derivatives can be used as hole transporting layers in organic light-emitting diodes.