Study of the effects of NaCl or NaOH as sodium dopant precursors in p-type nanocrystalline Cu2O thin films

Publication date: April 2020Source: Materials Science in Semiconductor Processing, Volume 109Author(s): L. Hill-Pastor, T. Díaz-Becerril, R. Romano-Trujillo, M. Galván-Arellano, R. Peña-SierraAbstractThe effects of sodium chloride (NaCl) or sodium hydroxide (NaOH) used to control the p-type conductivity of cuprous oxide Cu2O thin films by reactive thermal annealing (ReTA) at 550 °C in low oxygen content applied to NaX/Cu2O (X = Cl or OH) bilayers were studied. NaX nanolayers were deposited by dipping the Cu2O films in their saturated solutions. It has been reported that annealing Cu2O films covered with NaCl powders increased their hole concentration, but the effects of the X− ions on the oxide film had not been clarified. Here we report that the ReTA process applied to NaX/Cu2O bilayers reduces the electrical resistivity and increases the hole mobility, but the surface characteristics were also modified. During the ReTA process, CuXn (n = 1, 2) chemically reactive compounds are produced etching the film surface. The resistivity of the films was reduced by a factor of ten with respect to the as-grown Cu2O films by the Na incorporation and the hole mobility increased by the surface passivation due to the CuXn surfactant compounds produced during the ReTA process. The ReTA process applied during short periods the Cu2O phase was also stabilized according to the experimental results.
Source: Materials Science in Semiconductor Processing - Category: Materials Science Source Type: research