Hetero-epitaxial growth of BexZn1-xSe on Si(001) and GaAs(001) substrates

The growth of BexZn1-xSe alloys has been investigated by molecular beam epitaxy on Si(0 0 1) and GaAs(0 0 1). The best results concerning BeSe have been obtained on Si(0 0 1) substrates with miscut of 4 degrees towards [1 1 0], at growth temperatures of at least 500 degrees C and with low growth rates of 0.1-0.2 Angstrom/s. A lattice parameter of 5.139 +/- 0.002 Angstrom has been measured on a 1 mu m thick layer. The direct bandgaps of BexZn1-xSe alloys have been measured through photoluminescence and reflectivity experiments. However, these optical studies have not been able to draw yet a conclusion on the existence of a direct-indirect bandgap transition. (C) 1998 Elsevier Science B.V. All rights reserved.