Photoemission investigation of MBE-grown HgSerCdSe heterostructures

The surface termination and geometric structure of molecular beam epitaxially MBE.-grown HgSe 001.has been studied by means of X-ray photoelectron spectroscopy XPS.and high-resolution low-energy electron diffraction. The surface exhibit a c 2=2.reconstruction and is terminated by Hg. In addition, the valence band offset of the HgSerCdSe 001. heterostructure has been investigated by k-resolved ultraviolet photoemission UPS.. Special care was taken to determine the true position of the VB maximum in the Brillouin zone G-point.by using Ar–I excitation during the angle-dependent UPS measurements. Thus, the valence band discontinuity was determined as 0.58"0.05 eV. This value and recent results for the HgTerCdTe heterojunction support the trend expected by theory predicting a larger DEVBO for selenides than for tellurides. q2000 Elsevier Science B.V. All rights reserved