Strain induced bandgap engineering in multiferroic CuO nanoparticles: Competing micro-strain and geometrical size in nanometer scales

Interband electronic transitions and optical phonon modes in size-dependent multiferroic BiFeO3 nanoparticles

“…The reduction in band gap with decreasing NP size contradicts the quantum confinement effect (QCE), supporting the earlier reported studies in the bismuth ferrite, and CuO NP systems. 52,53 These observed band gap values are less than the reported bulk BFO band gap. 46,54 This unusual trend in the variation in E g values is attributed to the strain-modulated band gap engineering in the BFO nanoparticles.…”

“…The reduction in band gap with decreasing NP size contradicts the quantum confinement effect (QCE), supporting the earlier reported studies in the bismuth ferrite, and CuO NP systems. 52,53…”

Structure Composition, Morphology and Optical Properties of Chemically Synthesized CuO Nanoparticle

“…In the present study, defects prompted effects are dominating over particle size effect. As a result, a slightly higher band gap is obtained for as-synthesized CuO nanoparticles [16]. For direct transition, their optical absorption near the band edge follows the equation.…”