JOURNAL OF PHYSICS-CONDENSED MATTER, cilt.18, sa.26, ss.6057-6064, 2006 (SCI-Expanded)
The emission band spectra of undoped Tl4In3GaSe8 chain crystals have been studied in the 16-300 K temperature range and the 535-740 nm wavelength range. Two visible photoluminescence bands centred at 589 and 633 nm were observed at T = 16 K. Variations of both bands have been investigated over a wide range of laser excitation intensity ( 3 x 10(-4) -1.2 W cm(-2)). Radiative transitions with energies of 2.10 and 1.96 eV from two upper conduction bands to two shallow acceptor levels (0.03 and 0.01 eV), respectively, were suggested as being responsible for the observed bands in Tl4In3GaSe8 crystal, which is non-transparent in the visible range.