Photoemission studies of ZnSe epilayers grown on GaAs(111)B surface

Abstract

Surface electronic structure in transition-metal (Cr and Mn) doped GaAs (001) studied by in situ photoemission spectroscopy Appl.Growth mode and defect generation in ZnSe heteroepitaxy on Te-terminated GaAs (001) surfaces J. Vac. Sci. Technol. B 15, 1254 (1997); 10.1116/1.589446 Structural properties of ZnSe layers grown on (001) GaAs substrates tilted toward [110] and [010] J.The growth and characterization of ZnSe epilayers on GaAs͑111͒B was studied. Insight into the formation mechanism of this type of surface, interface, and bulk has been provided by photoemission spectroscopy. When Zn and Se are deposited, Se reacts with As to form Se-As bonds. Therefore, the electron mean free path obtained from the intensity variation of the surface As layer is less than that from the As bulk intensity since its emission is transferred from the surface peak into chemically shifted As peak. Deposition of ZnSe results in a substrate core level shift of 0.59 eV toward lower binding energy. A value of 0.91 eV for the valence band offset, with the valence band maximum of ZnSe below that of GaAs, was obtained.

Surface, interface and bulk properties of GaAs(111)B treated by Se layers

“…This shows that the As intensity ratio of I (As2)/I (As1) increases from 0.9 at polar angle θ = 0 • to 2.2 at 70 • , and the intensity ratio of I (As3)/I (As1) increases from 0.28 to 0.62. Our assignment is in agreement with previous experimental results [11,12] where the lowest kinetic energy peak component is assigned to the top As layer, and the highest kinetic energy peak component is attributed to the second surface As layer.…”

“…A 1.5 µm thickness GaAs(111)B epilayer was grown by MBE at Cardiff University, and protected with a micrometre thick As cap during transfer to BESSY1. A clean substrate GaAs surface was prepared in the growth chamber by gradually heating to around 450 • C, as described elsewhere [10,11]. After a sharp 2 × 2 LEED pattern appeared, the sample was transferred to the analyser chamber where angle-resolved photoemission spectra of Ga 3d, As 3d and valence bands were acquired to characterize the observed surface reconstruction.…”

“…A lineshape analysis procedure for the core level spectra was employed to probe the composition of the clean surface and the reactions occurring at evolving interfaces. The basic method of analysis is the deconvolution of each core level lineshape into components representative of the surface, the bulk and the interface using a standard least-squares fitting routine as described elsewhere [10,11]. The lineshape deconvolution for all core levels was performed in a consistent way, in which we used a minimum number of components and fixed the spin-orbit splitting and the Lorentzian widths in the fit.…”

“…The lineshape deconvolution for all core levels was performed in a consistent way, in which we used a minimum number of components and fixed the spin-orbit splitting and the Lorentzian widths in the fit. The starting values for the spin-orbit splitting, the branching ratio and the Lorentzian and Gaussian widths were obtained from clean surface data in the literature [6,7,[10][11][12][13]. The parameters acquired by fitting angle-integrated (from −90 • to +90 • ) spectra were those employed to decompose the angle-dependent emission of the same core level, for which only the intensities of each component were allowed to vary with angle in the fit.…”

MBE growth of MgSe thin films on ZnSe/GaAs(001) substrates

“…Unlike ZnSe, which has been extensively studied [17], only very few data are available for zinc blende MgSe deposition on ZnSe. No measured value of the zinc blende MgSe lattice constant has been reported before 1998 [14].…”