Photoelectrochemistry of GaInP{sub 2} capped p-GaAs electrodes

Conference · Tue Oct 01 04:00:00 EDT 1996

OSTI ID:370820

Koval, C A; Watts, D K ^[1]

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1. Univ. of Colorado, Boulder, CO (United States)

The efficient performance of GaAs in photoconversion devices requires surface treatment to minimize surface recombination, enhance minority carrier lifetimes, increase the rate of electron transfer, and/or minimize photocorrosion at the surface. GaAs/GaInP interfaces have been shown to provide significantly more stable surfaces than comparable GaAs/AlGaAs junctions. However, there is very little reported on the photoelectrochemical behavior of GaInP capped GaAs electrodes. We investigated the photoelectrochemical behavior of an 80 {Angstrom} Ga{sub 0.52}In{sub 0.48}P capped p-GaAs, rotating disk electrode in acetonitrile solutions containing metallocene redox couples with reduction potentials ranging between -03 V and -1.2 V versus Ag/0.1 M AgNO{sub 3}. The semiconductor material investigated was prepared at NREL by MOCVD and consisted of a thin layer of GaInP{sub 2} grown onto p-GaAs. Current-potential and interfacial capacitance measurements obtained in the dark indicate minimal band edge movement with changes in solution potential. However, analysis of the shape of the voltammograms and the Mott-Schottky plots obtained in the light, indicates a negative potential shift in the position of the band edges upon illumination. The extent of band edge movement depends on the concentration of the oxidized form of the redox couple in solution. The results indicated the existence of high energy, band gap surface states within 0.4-0.5 eV of the conduction band edge.

• OSTI ID: 370820
• Report Number(s): CONF-960376--
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
CAPACITANCE
ELECTRICAL PROPERTIES
ELECTRODES
ELECTRON TRANSFER
GALLIUM ARSENIDES
GALLIUM PHOSPHIDES
INDIUM PHOSPHIDES
INTERFACES