TIGa0.8Sb0.2S2 single crystals were grown by the Bridgman-Stockbarger method. The phtotoconductivity spectrum of the single crystal was measured at 20 K. Four peaks at 504 nm (2.460 eV), 525 nm (2.361 eV), 571 nm (2.171 eV), and 584 nm (2.123 eV) were observed in the spectrum. The high intensity-principal peak was observed at 525 nm and was described to be due to its indirect energy band gap. The peak at 504 nm was described to correspond to the direct energy band gap. The peaks at 571 and 584 nm Could be attributed to the electron transition from the valence band to the donor levels with the activation energy of 0.186 and 0.234 eV, respectively. (C) 2003 Elsevier B.V. All rights reserved.