Optical and photophysical portrayal of Sm3+ complexes possessing two band gaps for relevance in solar cells and photovoltaic devices

Abstract

Octa-coordinated samarium (III) complexes were synthesised using a fluorinated β-keto carboxylic acid (L) as prime ligand and N-donor systems as auxillary ligands, by ecologically desirable grinding method. The photoluminescent properties were investigated in powder and solution form. The characteristic emission at ∼605 nm (solid state) and ∼599 (solution phase) relative to 4G5/2 → 6H7/2 transition is accountable for the bright vermillion color of complexes. Quantum yield and colorimetric parameters were obtained for solid and solution state. CCT and color purity value characterise these complexes as warm orange light source. Reflectance spectra of solid complexes were fitted nonlinearly to procure optical band gap and Urbach band tail width. Two band gaps were reported in each complex, hence can have materiality in solar cell and photovoltaic devices. The FWHM obtained for most emissive transition (4G5/2 → 6H7/2) is found to be comparable with Nd-doped fluorophosphates glass. Energy transfer pathway studied for all the synthesised complexes, affirmed the effective energy transfer from ligands to Sm3+ ion. Investigation of antimicrobial behaviour of complexes revealed either higher or similar activity with respect to the ligand.