Electronic properties of the Cs covered GaAs(100) Ga-rich surface

• Published in: Solid state communications 2000-01, Vol.114 (5), p.285-289
• Main Authors: Benemanskaya, G.V, Daineka, D.V, Frank-Kamenetskaya, G.E
• Format: Article
• Language: English
• Subjects: A. Surfaces and interfaces; Condensed matter: electronic structure, electrical, magnetic, and optical properties; D. Electronic band structure; E. Photoelectron spectroscopies; Electronic structure and electrical properties of surfaces, interfaces, thin films and low-dimensional structures; Exact sciences and technology; Impurity and defect levels; energy states of adsorbed species; Physics; Surface and interface electron states
• ISSN: 0038-1098; 1879-2766
• DOI: 10.1016/S0038-1098(00)00050-8

Room temperature adsorption of Cs on the GaAs(100) Ga-rich surface has been studied in ultrahigh vacuum with threshold photoemission spectroscopy. The surface band structure has been investigated in a wide range of Cs coverages. Two Cs-induced bands A 1 and A 2 below the E F are revealed at low coverages. The evolution of the bands completes at coverage Θ∼0.7 ML corresponding to the saturation of Ga dangling bonds. At Θ>0.7 ML, the broad features P and C are found in the spectra. The modification of the spectra provides evidence of two adsorption phases with a strong and a weak Cs bonding. The results specify the A 1 and A 2 bands to be originated from local interaction of Cs-atoms with Ga dimers. The P and C features can be attributed to Cs surface plasmon and to plasmons excited in Cs quasi-2D or 3D clusters. The Cs/GaAs(100) Ga-rich interface is found to be semiconducting up to 0.9 ML.