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- Thursday, April 13, 2006
- Controlling charge-transfer processes at semiconductor/liquid junctions
- Published at:Not Found
Electrochimica Acta 51 (2006) 6487–6497.
H. S. Hilal* and J. A. Turner,
Abstract
The interfacial kinetics of charge transfer at n-GaAs/liquid junctions were controlled by anchoring positively charged species, such as tetra(-
4-pyridyl)porphyrinatomanganese(III), with the semiconductor surface. Unlike earlier adsorption techniques, the charges have been chemically
anchored to the semiconductor surface, in this work, via a ligand. The number of charges per site (attached molecule) ranged from +1 to +5. The
positive charges shifted the band-edges towards more positive potential values. The degree of shift increased with surface charge density. In the dark,
the flat band potential (measured by Mott–Schottky technique) and the onset potential were shifted by up to 300mV depending on surface charge
density. Relatively less of a shift was observed during illumination of the system. Other surface characteristics, such as conversion efficiency and
photoluminescence intensity, have been enhanced. The basis for these shifts and their implications with respect to control of interfacial processes
are discussed.
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