Two-Step Annealing Study of Cuprous Oxide for Photovoltaic Applications

The properties of large grain cuprous oxide (Cu2O) foils are explored after the implementation of a controlled postgrowth annealing process. P-type foils with a wide range of carrier density are demonstrated, enabling a promising processing window for wide bandgap solar cell devices. Hall measurements at room temperature show increased majority carrier concentration after nitrogen annealing and a reduction in mobility. The progressive change in resistivity with annealing temperature is shown, with values approaching 100 Ω·cm. Carrier recombination, measured by microwave photoconductance decay, shows a discrete change upon annealing.