Photocorrosion of n-GaAs and passivation by Na{sub 2}S: A comparison of the (100), (110), and (111)B faces

Journal Article · Thu Apr 03 04:00:00 EST 1997 · Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical

DOI:https://doi.org/10.1021/jp962852k· OSTI ID:535441

Miller, E A; Richmond, G L ^[1]

---

1. Univ. of Oregon, Eugene, OR (United States)

Photocorrosion of n-GaAs and passivation by Na{sub 2}S have been studied in a working photoelectrochemical cell as a function of crystal face orientation. Time-resolved photoluminescence studies of the (100), (110), and (111)B faces of n-GaAs show that Na{sub 2}S provides a similar degree of corrosion protection to the (100) and (110) faces, although the corrosion-induced surface states eventually formed at each interface are separated in energy by nearly 300 meV. Unlike (100) and (110), the (111)B surface is not passivated by Na{sub 2}. The high density of intrinsic surface states at the (111)B n-GaAs surface, and the lack of removal of these states by Na{sub 2}S, pins the Fermi level and prevents trap saturation. X-ray photoelectron spectroscopic studies of the three surfaces before and after Na{sub 2}S treatment show a significant degree of arsenic sulfide bonding on (100) and (110). The (111)B face shows very little As-S bonding, indicating that formation of interfacial sulfides plays an important role in the reduction of interfacial traps and passivation of the photocorrosion reaction. 44 refs., 11 figs., 3 tabs.

• DOE Contract Number: FG06-86ER45273
• OSTI ID: 535441
• Journal Information: Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical, Journal Name: Journal of Physical Chemistry B: Materials, Surfaces, Interfaces, amp Biophysical Journal Issue: 14 Vol. 101; ISSN 1089-5647; ISSN JPCBFK
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
40 CHEMISTRY
BINDING ENERGY
CORROSION
CORROSION PROTECTION
ELECTRON SPECTRA
GALLIUM ARSENIDES
INTERFACES
PASSIVATION
PHOTOCHEMICAL REACTIONS
PHOTOCURRENTS
PHOTOELECTROCHEMICAL CELLS
PHOTOLUMINESCENCE
SEMICONDUCTOR MATERIALS
SODIUM SULFIDES
SURFACES