The Al0.21Mn0.78PS3, Al0.15Cd0.83PS3, In0.20Cd0.70PS3 and Ga0.28Cd0.58PS3 compounds have been synthesized by the cation-exchange process used for other cationic species of the same family. These compounds were characterized by X-ray diffraction, Fourier transform infrared spectroscopy, ICP plasma analyses, photoconductivity and electrochemical impedance spectroscopy. The compounds synthesized show electrical conductivities (U) of the order of 10(-9) to 10(-10) S cm(-1) at 298 K and photoconductive effect. The physical properties of the new Al3+ materials reveal the same behavior as our previous report on In3+ and Ga3+ compounds. (C) 2002 Elsevier Science Ltd. All rights reserved.