Optical studies on composite Langmuir–Blodgett films containing ytterbium bis-phthalocyanine

Abstract

Abstract Langmuir films of pure ytterbium bis-phthalocyanine (YbPc2) molecules and its mixtures with calix[4]resorcinarene (C[4]RA) molecules were studied by UV–vis absorption spectra and surface pressure–area (II–A) isotherm measurements. Langmuir–Blodgett (LB) films of both pure YbPc2 and YbPc2–C[4]RA mixtures were produced and characterized with UV–vis spectra and surface plasms on resonance (SPR). In the case of LB films of pure YbPc2 molecules, values of 1.68 × 107 m−1 and 1.76% were found for the absorption coefficient at spectral maxima and the reflectance loss. Mixed YbPc2–C[4]RA films give smaller values depending on the mixing ratio. SPR measurements, made in two media with different refractive indices, yielded accurate values of thickness of 2.06 ± 0.06 nm and refractive index of 1.70 ± 0.02 for LB films of pure YbPc2 molecules. Electrochromic effects, driven by electrochemical oxidation/reduction of the Yb central atom, were registered in LB films of pure YbPc2 molecules by both UV–vis absorption spectra and SPR measurements.