Photoluminescence of Tl4HgI6 single crystals - A. I. Kashuba; M. V. Solovyov; A. V. Franiv; B. Andriyevsky; T. S. Malyi; V. B. Tsyumra; Ya. A. Zhydachevskyy; H. A. Ilchuk; M. V. Fedula (Low Temperature Physics, 2020)