Study of LiInSe₂ Single Crystals for the Thermal Neutron Detection

Lithium–indium diselenide (LiInSe₂) is a new semiconductor material, sensitive to the thermal neutrons. LiInSe₂ compound was synthesized from Li (99.99%), In (99.999%) and Se (99.999%). The growth of LiInSe₂ single crystals was performed using the vertical option of Bridgman–Stockbarger method. The crystals were characterized using the electrical conductivity and optical spectroscopy methods. Stoichiometric composition of the LiInSe₂ was confirmed by the high precision chemical analysis, as well as by X-ray diffraction. Compact ²⁵²Cf neutron source with the activity 6.3 × 10⁵ n/s allowed measuring amplitude characteristics and defining the optimal operating voltage for neutron detection. Time-of-flight neutron spectra were measured at the fast pulsed research reactor IBR-2 at the Joint Institute for Nuclear Research.