Electron beam induced Hg desorption and the electronic structure of the Hg depleted surface of Hg1−xCdxTe

Abstract

Auger electron spectroscopy (AES), x-ray photoemission spectroscopy (XPS), low energy electron diffraction (LEED), and angle-resolved ultraviolet photoemission spectroscopy (ARPES) were used to study the electron beam induced Hg desorption from a cleaved (110)Hg1−xCdxTe surface and the electronic structure of the Hg depleted surface. Solid state recrystallized Hg1−xCdxTe single crystals were used. It was found that the electron beam heating dominated the electron beam induced Hg desorption on Hg1−xCdxTe. At the electron beam energy used, the electron beam heating extended several thousand angstroms deep. However, the Hg depletion saturated after a few monolayers were depleted of Hg atoms. At the initial stage of Hg loss (only 3%), the surface band bends upward (more p type). The ARPES spectrum showed the loss of some E vs k dispersion after 22% Hg atoms were removed from the surface region, and no dispersion was observed after 43% Hg atoms were removed. These results have important implications on the electronic structure of the surfaces and interfaces of which the stoichiometry is altered.