OPTICAL AND STRUCTURAL-PROPERTIES OF ZN1-XBEXSE MIXED-CRYSTALS

Optical and structural properties of Zn1 - xBexSe bulk crystals in the range of composition 0 less than or equal to x less than or equal to 0.41 have been studied. These crystals were grown by Bridgman method u nder an argon overpressure. Transmission, absorption, photoluminescenc e and photoacoustic spectra as a function of composition were investig ated. It has been found that the crystal structure is of sphalerite ty pe. The crystal quality increases when the crystallization process of the same boule is performed more than once. In the investigated compos ition range the lattice constant decreases and the energy gap increase s with increasing beryllium content. From photoluminescence measuremen ts the excitonic energy gap about 3.64 eV at 40 K was estimated for th e highest obtained Be concentration (x = 0.41).