Picosecond photoluminescence studies of photocorrosion and passivation of n-GaAs in Na{sub 2}S-containing solutions

Journal Article · Thu Mar 23 04:00:00 EST 1995 · Journal of Physical Chemistry

DOI:https://doi.org/10.1021/j100012a037· OSTI ID:35458

Balko, B A; Miller, E A; Richmond, G L ^[1]

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

Passivation of n-GaAs by Na{sub 2}S in an electrochemical cell has been studied using photoluminescence decays and voltage dependence of photoluminescence intensity. A significant increase in the degree of passivation of the (100) n-GaAs surface is seen when the concentration of Na{sub 2}S is increased above approximately1 M. The observed passivation in higher concentrations of Na{sub 2}S eventually deteriorates with extended exposure to light. The corrosion that develops when the n-GaAs is in higher concentrations of Na{sub 2}S leads to traps that can be occupied at all voltages. This behavior is different from corrosion seen in lower concentrations of Na{sub 2}S in which the traps can only be occupied at voltages greater than V = 0.0 V. Decay measurements at flatband potential and at open circuit indicate no significant changes in surface-trapping velocity as the Na{sub 2}S concentration is changed from 0.008 to 1 M. This suggests that repinning or removal of surface traps is not responsible for the passivation that is observed upon increasing the Na{sub 2}S concentration. An increase in the rate of charge transfer across the interface as the Na{sub 2}S concentration in the electrolyte is increased appears responsible. 24 refs., 7 figs., 3 tabs.

• Sponsoring Organization: USDOE
• DOE Contract Number: FG06-86ER45273
• OSTI ID: 35458
• Journal Information: Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 12 Vol. 99; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

14 SOLAR ENERGY
36 MATERIALS SCIENCE
40 CHEMISTRY
CHARGE TRANSPORT
COATINGS
CORROSION
DECAY
ELECTRIC POTENTIAL
EXPERIMENTAL DATA
GALLIUM ARSENIDES
N-TYPE CONDUCTORS
NUMERICAL DATA
PASSIVATION
PHOTOELECTROLYTIC CELLS
PHOTOLUMINESCENCE
POTENTIALS
SEMICONDUCTOR MATERIALS
SODIUM SULFIDES
TRAPS