Surface Dipole Formation and Lowering of the Work Function by Cs Adsorption on InP(100) Surface

Journal Article · Fri Jun 08 04:00:00 EDT 2007 · J.Vac.Sci.Technol.A Vac.Surf.Films 25:1351,2007

DOI:https://doi.org/10.1116/1.2753845· OSTI ID:908558

Sun, Y; Liu, Z; Pianetta, P

The Cs adsorption on InP(100) surface is studied with Synchrotron Radiation Photoelectron Spectroscopy. The charge transfer from Cs to the InP substrate is observed from the Cs induced In4d and P2p components, and this charge transfer results in surface dipole formation and lowering of the work function. The Cs4d intensity saturates at coverage of one monolayer (ML). However, a break point is observed at 0.5 ML, which coincides with the achievement of the minimum work function. This break point is due to the different vertical placement of the first and the second half monolayer of Cs atoms. Based on this information, a simple bi-layer structure for the Cs layer is presented. This bi-layer structure is consistent with the behavior of the charge transfer from the Cs to the InP substrate at different Cs coverages. This, in turn, explains why the work function decreases to a minimum at 0.5 ML of Cs and remains almost constant beyond this coverage. The depolarization of the surface dipoles is attributed to the saturation of charge transfer to the surface In atoms and the polarization of the Cs atoms in the second half monolayer induced by the positively charged Cs atoms in the first half monolayer.

• Research Organization: Stanford Linear Accelerator Center (SLAC)
• Sponsoring Organization: USDOE
• DOE Contract Number: AC02-76SF00515
• OSTI ID: 908558
• Report Number(s): SLAC-PUB-12551
• Journal Information: J.Vac.Sci.Technol.A Vac.Surf.Films 25:1351,2007, Journal Name: J.Vac.Sci.Technol.A Vac.Surf.Films 25:1351,2007; ISSN 0734-2101; ISSN JVTAD6
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
ADSORPTION
ATOMS
DEPOLARIZATION
DIPOLES
Other
MATSCI
PHOTOELECTRON SPECTROSCOPY
POLARIZATION
SATURATION
SUBSTRATES
SYNCHROTRON RADIATION
WORK FUNCTIONS