DIGITAL SIMULATION OF THE COULOSTATIC-FLASH RESPONSE AT A SEMICONDUCTOR/ELECTROLYTE INTERFACE

JOHN MARSH MARTIN, Purdue University

Abstract

The possible application of the semiconductor/electrolyte interface to solar energy conversion has stimulated considerable interest in the field of photoelectrochemistry. The technique of flash-induced coulostatic chronopotentiometry has been recently developed to study rapid charge transfer processes at the semiconductor/electrolyte interface. These studies may be able to provide valuable information concerning the factors which limit the stability and energy conversion efficiency if the experimental results can be interpreted correctly. The objective of the work presented here was to theoretically describe a coulostatic-flash experiment. Digital simulation was used to characterize the variables which influence the potential transients observed in these experiments. The results of these simulations were then used to interpret experimental data. The first section of this thesis provides a general introduction to the investigation. A review of solid state fundamentals needed for an understanding of the following work is introduced next. A description of the semiconductor/electrolyte interface, the transient techniques used to study it, and a brief introduction to digital simulation are given in the third section. The simulation results which follow, describe the influence of minority carrier lifetime, initial potential, illumination intensity, dopant density, carrier mobility, and charge transfer on the coulostatic-flash response. These results were then used to interpret experimental data, verifying the charge transfer contributions to the transient coulostatic signal.

Degree

Ph.D.

Subject Area

Analytical chemistry

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