Optical spectra of wide band gap BexZn1-xSe alloys

We report optical measurements (photoluminescence, Raman scattering, and in frared reflectance) of direct band gap and of optical phonon energies of Be xZn1-xSe alloys grown by MBE on (001) GaAs substrates for a wide range of B e concentrations. The high band gap of BeSe (5.15 eV) suggests the possibil ity of using isoternary alloys for ultraviolet optoelectronic applications. BexZn1-xSe has the unique advantage that it can be lattice matched to Si a t about x=0.5. We observed a strong linear shift of the BexZn1-xSe direct b and gap to higher energies with increasing Be content (to 3.63 eV for x=0.3 4). Furthermore, optical phonon parameters for the entire range of BeSe con tent have been obtained. Finally, polarized infrared and Raman spectra reve aled local atomic ordering (anti-clustering) effects in the group-II sublat tice. (C) 1999 American Institute of Physics. [S1063-7826(99)02509-0].