Wide-band-gap ZnMgBeSe alloys grown onto GaAs by molecular beam epitaxy

We have investigated ZnMgBeSe-quaternary wide-band-gap alloys grown by mole cular beam epitaxy lattice-matched or moderately strained onto (0 0 1)-GaAs substrates, paying attention to preserve conditions compatible with the gr owth of other ZnSe-based compounds. Two-dimensional growth is obtained up t o band gaps as high as 3.5eV, as measured by reflectivity, Intense and narr ow photoluminescence is observed for all samples, up to 3.6eV. X-ray linewi dths as narrow as 10 arcsec are obtained which compare very well with the s ubstrate value of 7 arcsec. This reveals the high crystal quality of the ep itaxial material. Our results show that this material is well suited for UV A detection. (C) 2001 Elsevier Science B.V. All rights reserved.