Crystal Growth and Optical Properties of Cd1-x-yMnxZnyTe Diluted Magnetic Semiconductors

Abstract

The mechanical and the optical properties of Cd$_{1-x-y}$Mn$_x$Zn$_y$Te diluted magnetic semiconductors (DMS)(x = 0.35, 0 $\leq$ y $\leq$ 0.65) grown by using the vertical Bridgman method were investigated. The lattice constant decreased from 6.4383 \AA ~ to 6.1225 \AA ~ as shown from X-ray diffraction experiments, the bandgap energy obtained from the absorption measurements increased from 2.17 eV to 2.55 eV and the temperature coefficients of Varshni's empirical formula, $\alpha$ and $\beta$, were increased together with increasing Zn composition y. The exciton peaks (A$^0$, X) and (D$^0$, X) bound to neutral acceptor and to neutral donor were appeared at 2.1385 eV and 2.1528 eV, respectively, These was also a characteristic peak originating from Mn$^{2+}$ ions at around 1.97 eV. That (A$^0$, X) peak disappeare at above 60 K decreasing the luminescence intensity abruptly and did not appeared for the amples with Zn compositions of above 0.1 mole fraction. These kinds of DMS should be promising material, for various applications because of the changeability of its bandgap energy and lattice constant while etaining its magnetic property.