Growth and physical characterization of AgGa1−xInxSe2 (x=0.5) single crystals grown by modified vertical Bridgman method

Abstract

AgGa1−xInxSe2 (x=0.5) polycrystalline material was successfully synthesised from high purity elements by the melt and temperature oscillation method. Large size and crack-free AgGa0.5In0.5Se2 single crystals were grown using a double wall quartz ampoule with accelerated crucible rotation technique (ACRT) by modified vertical Bridgman method. The unit cell parameters were confirmed by single crystal X-ray diffraction analysis. The composition of AgGa0.5In0.5Se2 was measured using energy dispersive spectrometry (EDS). The insignificant change in atomic percentages of Ag, Ga, In and Se along the ingot further reveals that the composition throughout its length is fairly homogeneous. The transmittance spectra of AgGa0.5In0.5Se2 single crystal was achieved in the NIR region and high transmittance of the crystals in the mid-IR region was revealed. The absorption edge of the material is near 881nm and the optical band gap energy is 1.4eV. Thermal property of AgGa0.5In0.5Se2 has been studied using Differential scanning calorimetry (DSC) technique and it confirms that the increase in Indium content reduces the super-cooling temperature. Electrical property is measured using Hall Effect measurements and it confirms the n-type semiconducting nature.