magneto-optical properties of gap single crystal

The temperature dependence of magneto-optical and magneto-photoconductivity measurements were carried out in the range of (200-330) K. A home made optical cryostat was used for the measurements. The measured room temperature value of the energy gap was found to be 2.211 eV. The temperature coefficient of energy gap was found to be -5.48×10-4 eV/K obtained by the optical absorption method and -4.90×10-4 eV/K from the measurements of photoconductivity. The magnetic field coefficient of energy gap was found to be temperature dependent with values of 1.34×10-3 eV/Tesla at 202 K and 2.67×10-3 eV/Tesla at room temperature, when the field used was up to 2.2 Tesla. The reduced effective mass of carriers are also calculated from both techniques and found to be changing from 0.034 m0 to 0.021 m0 when magneto-optical data was used in the calculations and from 0.052 m0 to 0.032 m0 when magneto-photoconductivity data was used as the temperature changed from 220 K to 330 K respectively.