Band gap tuning and p to n-type transition in Mn-doped CuO nanostructured thin films

Here we discuss the synthesis of copper (II) oxide (CuO) and manganese (Mn)-doped CuO thin films varying with 0 to 8 at% Mn using the spray pyrolysis technique. As-deposited film surfaces comprised of agglomerated spherical nanoparticles and a semi-spongy porous structure for 4 at% Mn doping. Energy dispersive analysis of X-rays confirmed the chemical composition of the films. X-ray diffraction spectra showed a polycrystalline monoclinic structure with the predominance of the ((1) over bar 11) peak. Optical band gap energy for direct and indirect transitions was estimated in the ranges from 2.67-2.90 eV and 0.11-1.73 eV, respectively. Refractive index and static dielectric constants were computed from the optical spectra. Electrical resistivity of CuO and Mn-doped CuO (Mn:CuO) thin films was found in the range from 10.5 to 28.6 Omega.cm. The tiniest electron effective mass was calculated for 4 at% Mn:CuO thin films. P to n-type transition was observed for 4 at% Mn doping in CuO films. Carrier concentration and mobility were found in the orders of 10(17) cm(-3) and 10(-1) cm(2)/(V.s), respectively. The Hall coefficient was found to be between 9.9 and 29.8 cm(3)/C. The above results suggest the suitability of Mn:CuO thin films in optoelectronic applications.

Automated summary

In this study, copper (II) oxide thin films doped with different manganese concentrations were synthesized using the spray pyrolysis technique. The effects of manganese doping on the crystal structure, optical properties and electrical properties of the films were investigated. The results suggest that manganese-doped copper (II) oxide thin films have potential applications in optoelectronic devices.