Investigation of the physical properties of Tl2InGaSe4 crystals رسالة ماجستير

Abstract

In this thesis, we have explored the physical properties of Tl2InGaSe4 single crystals, by means of structural, optical and electrical investigation. A layered nature of the crystal which shown in scanning electron microscope Contributed in nanotechnology application. The temperature dependent X-ray analysis in the temperature range of 300-470 K has shown that the crystals which exhibit both of the monoclinic and tetragonal phases have tendency to make the monoclinic structure more dominant of the tetragonal. The estimated grain size, microstrain, defect density and stacking faults are all observed to be sensitive to the temperature dependent structural modifications. Consistently the studies of the temperatures dependent energy band gap have shown that the energy bandgap linearly decreases with increasing temperatures. In addition, the illumination dependent current-voltage characteristics have shown that the crystals with high sensitivity and less dependence of barrier height on light intensity. Furthermore, the impedance spectroscopy analysis in the frequency domain of 10-1800 MHz, revealed possible tunability of the capacitance nominating the crystals for use as varicap devices