New developments in the heteroepitaxial growth of Be-chalcogenides based semiconducting alloys
We have studied the heteroepitaxial growth of Zn(Mg)BeSe alloys on both GaAs and Si substrates. X-ray measurements show that ZnMgBeSe quaternary alloys can be grown with a high structural quality on GaAs(001). Linewidths as low as to 20 arcsec have been obtained from double x-ray diffraction and the etch pit density is in the range of 10−3 cm−2. The growth of ZnBeSe ternary alloys on vicinal Si(001) substrates has been investigated. Optical properties of Zn0.55Be0.45Se which is lattice-matched to silicon have been studied by photoluminescence and reflectivity and a fundamental bandgap E0 of 3.85 eV has been measured. Therefore, this material is a potential candidate for ultraviolet B detection. However, it is important to note that these measurements are not conclusive about the direct nature of alloys bandgaps.