Electrical phase transitions on the alkali-metal-adsorbed Si(001) surfaces

Journal Article · Thu May 01 04:00:00 EDT 1997 · Physical Review, B: Condensed Matter

DOI:https://doi.org/10.1103/PhysRevB.55.12906· OSTI ID:503698

Lee, K; Chung, J ^[1]

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1. Physics Department, Basic Science Research Institute, Pohang University of Science and Technology, San 31 Hyoja Dong, Pohang 790-784 (Korea)

The adsorption of alkali metals (AM{close_quote}s) on the Si(001) surface has been studied using high-resolution electron-energy-loss spectroscopy. We find that the metallization at low AM coverages manifests itself with a unique surface plasmon excitation, which turns out to be common to the AM (Li,Na,Cs)/Si(001) surfaces. With increasing AM coverage, these AM-induced metallic surfaces become semiconducting again revealing the characteristic metal-semiconductor transitions (MST{close_quote}s) at the onset of the first ordered structures: (4{times}1) and (2{times}3) for Na and Cs adsorption, respectively. We invoke a mechanism leading to a band insulator to understand such a MST accompanying a disorder-order structural transition. In addition, the distinctly different electrical properties of the AM saturated surfaces, semiconducting for Na and metallic for Cs, are attributed to the availability of some excess adatoms beyond 1 monolayer at room temperature. {copyright} {ital 1997} {ital The American Physical Society}

• OSTI ID: 503698
• Journal Information: Physical Review, B: Condensed Matter, Journal Name: Physical Review, B: Condensed Matter Journal Issue: 19 Vol. 55; ISSN PRBMDO; ISSN 0163-1829
• Country of Publication: United States
• Language: English

Related Subjects

66 PHYSICS
ADSORPTION
ALKALI METALS
CHEMICAL BONDS
ELECTRICAL PROPERTIES
ELECTRONIC STRUCTURE
ENERGY GAP
HYBRIDIZATION
INTERFACES
PHASE TRANSFORMATIONS
PLASMONS
SILICON
SOLID-STATE PLASMA