VALENCE BAND STUDIES OF CLEAN AND OXYGEN EXPOSED GAAS(110) SURFACES

被引：75

作者：

PIANETTA, P ^{[1
]}

LINDAU, I ^{[1
]}

GREGORY, PE ^{[1
]}

GARNER, CM ^{[1
]}

SPICER, WE ^{[1
]}

机构：

[1] STANFORD UNIV,STANFORD SYNCHROTRON RADIAT PROJECT,STANFORD,CA 94305

来源：

SURFACE SCIENCE | 1978年 / 72卷 / 02期

基金：

美国国家科学基金会;

关键词：

D O I：

10.1016/0039-6028(78)90297-2

中图分类号：

O64 [物理化学（理论化学）、化学物理学];

学科分类号：

070304 ; 081704 ;

摘要：

We found, by correlating band bending, ultraviolet photoemission spectroscopy, and partial yield spectroscopy measurements, that Fermi level pinning at midgap of n-type GaAs(110) is caused by extrinsic states. The exact nature of these states is not yet clear, but the surfaces with Fermi level pinning were strained as evidence by a smeared valence band emission. This smearing was removed by as little as one oxygen per 104 to 105 surface atoms. This implies that the oxygen has very long range effects in causing spontanesous but small rearrangement of the surface lattice and removing surface strains. When about 5% of a monolayer of oxygen is adsorbed, a major change in the electronic structure takes place. Again, the oxygen coverage is very small, which suggests long range effects now leading to a fairly large rearrrangement of the surface lattice. Finally, from comparing the oxygen induced emission for exposures greater than 107 L O2, with the spectra from gas photoemission measurements on molecular oxygen, we suggest that the oxygen is chemisorbed as a molecule on the (110) surface of GaAs. © 1978.

引用

页码：298 / 320

页数：23

共 30 条

[1] ELECTRONIC-STRUCTURE AND ATOMIC CONFIGURATION AT CLEAVAGE SURFACE OF ZINCBLENDE COMPOUNDS [J].