Energy transfer mechanism and optoelectronic properties of (PFO/TiO2)/Fluorol 7GA nanocomposite thin films

Abstract Energy transfer between poly (9,9'-di-n-octylfluorenyl-2,7-diyl) (PFO) as a donor in presence of TiO 2 nanoparticles (NPs) and Fluorol 7GA as an acceptor with different weight ratios has been investigated by steady-state emission measurements. Based on the absorption and fluorescence measurements, the energy transfer properties, such as quenching rate constant ( k SV ), energy transfer rate constant ( k ET ), quantum yield ( ϕ DA ), and lifetime (τ DA ), of the donor in the presence of the acceptor, energy transfer probability ( P DA ), energy transfer efficiency ( η ), energy transfer time (τ ET ), and critical distance of the energy transfer ( R o ) were calculated. Forster-type energy transfer between the excited donor and ground-state acceptor molecules was the dominant mechanism responsible for the energy transfer as evidenced by large values of k SV , k ET , and R o . Moreover, these composite materials were employed as an emissive layer in organic light-emitting diodes (OLEDs). Additionally, the optoelectronic properties of OLEDs were investigated in terms of current density–voltage characteristics and electroluminescence spectra.