Study of the effects of NaCl or NaOH as sodium dopant precursors in p-type nanocrystalline Cu2O thin films. (April 2020)

• Record Type: Journal Article
• Authors: Hill-Pastor, L.; Díaz-Becerril, T.; Romano-Trujillo, R.; Galván-Arellano, M.; Peña-Sierra, R.
• Is Part Of: Materials science in semiconductor processing. Volume 109(2020)
• Publication Date: 2020-04
• Subjects: Cuprous oxide -- Sodium doping -- NaCl -- NaOH -- Reactive thermal annealing; Semiconductors -- Periodicals; Integrated circuits -- Materials -- Periodicals; Semiconducteurs -- Périodiques; Circuits intégrés -- Matériaux -- Périodiques; Electronic journals; 621.38152
• DOI: 10.1016/j.mssp.2020.104914
• Languages: English
• ISSNs: 1369-8001

Abstract

Abstract: The effects of sodium chloride (NaCl) or sodium hydroxide (NaOH) used to control the p-type conductivity of cuprous oxide Cu2 O thin films by reactive thermal annealing (ReTA) at 550 °C in low oxygen content applied to NaX/Cu2 O (X = Cl or OH) bilayers were studied. NaX nanolayers were deposited by dipping the Cu2 O films in their saturated solutions. It has been reported that annealing Cu2 O 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/Cu2 O 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 Cu2 O 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 Cu2 O phase was also stabilized according to the experimental results. Highlights: The use of the NaX (X = Cl, X = OH) nano-layers etches the copper-oxide film surface. Sodium incorporation in the NaX/Cu2 O bilayers improved the electrical resistivity. The NaX liquid compounds formed in the annealed process improve the hole mobility.