Preparation and characterization of the semiconductor CuMnO2 by sol-gel route

Nadia Benreguia (1) , Antoine Barnabé (2) , Mohamed Trari (1)

1 USTHB - Université des Sciences et de la Technologie Houari Boumediene = University of Sciences and Technology Houari Boumediene [Alger]
2 CIRIMAT - Centre interuniversitaire de recherche et d'ingenierie des matériaux

Nano crystallites of the crednerite CuMnO2 are prepared by sol–gel method with two-step annealing process. The powder heated at 450°C under air flow shows a mixture of CuO, Mn2O3 and CuxMn3−xO4. However, when calcined at 900°C under N2 atmosphere, the crednerite CuMnO2 with a monoclinic structure (space group: C2/m) is obtained. The Raman spectrum shows a single peak at 679cm−1 assigned to A1g mode whereas the infrared analysis confirms the linearity of CuO23− units. The optical transition at 1.70eV, determined from the diffuse reflectance is attributed to the inter-band d-d transition of Cu+ ion. The oxide exhibits semiconducting properties with an activation energy of 0.21eV. The photo-electrochemical measurement shows p-type conduction due to O2− insertion in the two dimensional lattice. The flat band potential (+0.12 VSCE), indicates a cationic character of both valence and conduction bands deriving from Cu+: 3d orbital.

Mots clés: Sol–gel method; Scanning electron microscopy; Raman spectrum; Optical property; Crednerite CuMnO2

Domaines: Matériaux; Matériaux

Nadia Benreguia, Antoine Barnabé, Mohamed Trari. Preparation and characterization of the semiconductor CuMnO2 by sol-gel route. Materials Science in Semiconductor Processing, 2016, 56, pp.14-19. ⟨10.1016/j.mssp.2016.07.012⟩. ⟨hal-02378792⟩