Investigation of optical property in LiInSe2 single crystal grown by Bridgman Stockbarger method using stepper translations for mid IR laser application

• With dimension of 8 mm×40 mm NLO LiInSe2 single crystal was grown by Bridgman–Stockbarger method using stepper translation for mid-IR application.
• Homemade graphite crucible was used to grow quality LiInSe2 crystal.
• 80% transmittance achieved in the region of Mid IR.

LiInSe2 polycrystalline material was synthesized in a horizontal muffle furnace with the help of a mechanical motor. LiInSe2 single crystal has successfully been grown by modified Bridgman furnace using stepper translation. The grown crystal was subjected to various characterizations such as Powder X-ray Diffraction (XRD), Single crystal X-ray Diffraction, High Resolution X-ray Diffraction (HRXRD), Fourier transform infrared spectroscopy (FTIR), Ultraviolet–Visible-Near Infrared spectroscopy (UV–Vis–NIR), Photoluminescence and Micro Raman spectroscopy. The grown LiInSe2 crystal was confirmed by single crystal and powder X-ray diffraction analyses. The FTIR transmission of grown LiInSe2 single crystal was found to be around 80% which is being used in the field of mid Infrared laser, Lidar sensor, and optical parametric conversion. The band gap energy 1.85 eV was calculated from absorption spectrum. The cut off wave length is 617 nm for LiInSe2. The photoluminescence spectrum was observed around 598 nm at ambient temperature, corresponding energy is 2.07 eV. The structural and compositional uniformities of LiInSe2 were studied using micro-Raman scattering spectroscopy at room temperature. The insignificant change in the Full width at half maximum (FWHM) of the Г1 (W1) measured at different regions of the crystal further reveals that the composition throughout its length is fairly uniform.