Synthesis, structural modelling and photoluminescence of Tb(III) polymeric complexes for solution-processed OLEDs

Current manufacturing technologies for OLEDs involve the use of expensive high vacuum techniques and call for thermal stability requirements which are not fulfilled by many materials. These problems disappear when the OLED films are deposited directly from solution. In this study, we have synthesized, modelled by semi-empirical quantum chemistry methods and characterized the optical properties of two novel Tb(III) complexes with carboxylic acids, which can be readily used as “complex-only” emissive layers in wet-processed OLEDs. Upon excitation in the UV region, very efficient energy transfer from the ligands to Tb3+ takes place, giving rise to intense green emission, both in powder and as a thin film. The good quantum efficiencies (31.3% and 24.7%, respectively) and adequate thin film forming properties make these materials promising chromophores for cost-effective OLEDs.