Influence of La doping on the microstructure and optoelectronic behavior of CuO thin films

Lanthanum-doped CuO thin films were synthesized via a cost-effective spray pyrolysis technique, with doping concentrations ranging from 2 to 10 at.%. Structural, morphological, optical, electrical, and photoluminescence properties were comprehensively investigated. XRD confirmed monoclinic CuO structure and successful La incorporation, with crystallite size peaking at 6 at.% doping. SEM-EDS analyses revealed uniform surface morphology and verified elemental composition, while UV–Vis spectroscopy indicated doping-dependent bandgap modulation. Doping has enhanced optical absorbance and 8 at.% La doped CuO samples showed maximum absorbance. Raman spectra showed phonon confinement effects through redshifts and peak broadening. PL lifetime studies revealed the passivation of non-radiative recombination centers, particularly at moderate doping levels. First-principles simulations corroborated experimental observations, revealing charge redistribution and improved hole conductivity due to La substitution. These findings establish La doping as a viable strategy to engineer the optoelectronic properties of CuO thin films for photovoltaic and sensor applications.