Photoemission study of the Na/ZnSe„100... interface
نویسندگان
چکیده
We report on a comprehensive study of the ZnSe(100)-c(232)-Na interface using x-ray and UV photoemission, and x-ray-induced Auger spectroscopy. Spectra were taken after stepwise Na deposition onto a clean c(232)-reconstructed ZnSe~100! surface at room temperature up to a saturation coverage of about 1 ML of Na and after annealing. Based on the analysis of Auger parameters and of the relative intensity evolution of various Na, Zn, and Se species, we present the following model for the ZnSe(100)-c(232)-Na interface: below a coverage of 0.5 ML, Na is adsorbed on Zn vacancy sites; above 0.5 ML, a cation exchange reaction occurs between Na and Zn atoms; Zn atoms segregate on top of the Na overlayer forming metallic Zn. In addition, band-bending, surface dipole, valence-band and surface states will be discussed. @S0163-1829~99!02336-X#
منابع مشابه
Photoemission measurements of Ultrathin SiO2 film at low take-off angles
The surface and interfacial analysis of silicon oxide film on silicon substrate is particularly crucial in the nano-electronic devices. For this purpose, series of experiments have been demonstrated to grow oxide film on Si (111) substrate. Then these films have been used to study the structure of the film by using X-ray photo emission spectroscopy (XPS) technique. The obtained results indicate...
متن کاملSymmetry Analysis of ZnSe(100)/Air Interface By Second Harmonic Generation
We measured the polarized and azimuthal dependencies of optical second harmonics generation (SHG) on polished surfaces of ZnSe(100) single crystal surface in air, using a fundamental wavelength of 1.06μm. By considering both, the bulkand surfaceoptical nonlinearities within the electric dipole approximation, we analysed the data for all four combination of pand s-polarized incidence and output....
متن کاملELECTRON ACCUMULATION AT THE n-ZnSe/n-GaAs INTERFACE
Evidence for electron accumulation in the ZnSe side of n-ZnSe/n-GaAs heterostructures is presented. An n-GaAs buffer layer, approximately 1 pm thick, grown with low 1015 electronic concentration on a semi-insulating (100) GaAs substrate is fully depleted of electrons when an additional epilayer of nZnSe is grown on top of it. The n-GaAs epilayer electron concentration is restored when the ZnSe ...
متن کاملEffect of Vanadium Doping on Structure and Properties of ZnSe Films Prepared by Metal-Organic Vapor Phase Epitaxy
Vanadium-doped ZnSe films were epitaxially grown on (100) GaAs substrates by metal-organic vapor phase epitaxy. The crystal structure and the state of vanadium in the ZnSe crystal were investigated using X-ray diffractometry, infrared absorption, and photocurrent. It was revealed that zinc sites in the ZnSe crystal were substituted by vanadium atoms on the basis of the results of infrared absor...
متن کاملTunable Band Gap and Conductivity Type of ZnSe/Si Core-Shell Nanowire Heterostructures
The electronic properties of zincblende ZnSe/Si core-shell nanowires (NWs) with a diameter of 1.1-2.8 nm are calculated by means of the first principle calculation. Band gaps of both ZnSe-core/Si-shell and Si-core/ZnSe-shell NWs are much smaller than those of pure ZnSe or Si NWs. Band alignment analysis reveals that the small band gaps of ZnSe/Si core-shell NWs are caused by the interface state...
متن کامل