Effect of annealing and of cooling rates on n-GaAs electrode photoelectrochemical characteristics

Abstract

The effect of annealing of the n-GaAs semiconductor on its characteristics in photoelectrochemical (PEC) systems has been investigated. The photocurrent densities vs. potential plots were improved by annealing. Cell efficiency and short-circuit current densities were enhanced for the annealed n-GaAs. The effect of the rate of cooling of heated n-GaAs wafers was also investigated. It was found that the slowly cooled electrodes gave better dark current density vs. potential plots, for samples annealed below 600°C. For samples annealed at higher temperatures, quenching gave better dark-current density vs. potential plots. For n-GaAs, slowly cooled electrodes from temperatures below 600°C showed better photocurrent density vs. potential plots and higher efficiency. n-GaAs samples, quenched from temperatures above 700°C, showed better photocurrent density vs. potential plots and higher efficiency than their slowly cooled counterparts.