Investigations on synthesis, growth, electrical and defect studies of lithium selenoindate single crystals

LiInSe2 polycrystalline material was successfully synthesized from melt and temperature oscillation method (MTOM). The crystalline phase was confirmed by powder X-ray diffraction pattern. Crack free LiInSe2 single crystal of size 12 mm diameter and 32 mm length was grown using two zone tubular resistive heated furnace by modified vertical Bridgman–Stockbarger method with steady ampoule rotation. The grown LiInSe2 crystal was subjected to single crystal XRD, inductively coupled plasma-optical emission spectroscopy (ICP-OES), positron annihilation spectroscopy (PAS), Hall effect and dielectric measurements. Single crystal XRD measurement confirms the orthorhombic crystal system. ICP-OES analysis gives the crystal composition as Li0.81In1.01Se2.18. The average lifetime 278.03 ps in PAS measurements corresponds to vacancy clusters present in LiInSe2 crystal. Hall effect measurement confirms the n-type semiconductor nature. The dielectric permittivity and dielectric loss were obtained to be 9.8 and 0.108 respectively by capacitance measurements at room temperature for the frequency of 2 MHz.