[en] The photoconductivity of TlGaSe₂ layered single crystals are investigated in the temperature range 78-300 K. Both the ac-photoconductivity (ac-PC) and the spectral distribution of the photocurrent were studied at different values of light intensity, applied voltage and temperature. Dependences of carrier lifetime on light intensity, applied voltage and temperature have been investigated as results of the ac-PC and dc-photoconductivty (dc-PC) measurements. The temperature dependence of the energy gap width was described as a result of studying the dc-PC