Growth of cadmium sulfide single crystal by the sublimation method

A cadmium sulfide (CdS) single crystal was grown by the sublimation method without a seed crystal in a two-stage vertical electric furnace. The temperature difference, 15°C, between the source and growth parts in the growth tube was in good agreement with the calculated value of 14.7°C. From the diffraction patterns, the single crystal exhibits a hexagonal structure and its c-axis is along the symmetry axis of the growth tube. The measured carrier concentration and mobility of the CdS single crystal are about 2.90 × 10¹⁶ cm^-3 and 316 cm²/V·s, respectively, at room temperature. The energy bandgap obtained from photocurrent measurements follows Varshni's equation E_g(T) = 2.552 eV - (5.75 × 10^-3 eV)T² (T + 3743) rather than a linear relationship E_g(T) = 2.58 eV - (5.24 × 10^-4 eV K)T.