Energy transfer (In 3+ → Eu 3+ ) based Polyvinyl Alcohol polymer composites for bright red luminescence

Abstract A prominent sensitization effect of In 3+ ions is observed in In 3+ +Eu 3+ : PVA polymer composites under UV excitation. Consequently, it enhances the red emission performance of Eu 3+ ions in PVA system. We have successfully synthesized Eu 3+ : PVA, In 3+ : PVA and In 3+ +Eu 3+ : PVA polymer films by traditional solution casting method. The structural and ion-polymer interaction studies have been analyzed from XRD and FTIR spectral profiles. Eu 3+ doped PVA polymer composites are exhibited a red emission at 619 nm ( 5 D 0 → 7 F 2 ) under 396 nm ( 7 F 0 → 5 L 6 ) of excitation. Upon co-doping with In 3+ ions in different concentrations to the Eu 3+ : PVA polymer film, it exhibits predominant red emission than singly doped Eu 3+ : PVA under 396 nm of excitation due to energy migration from In 3+ to Eu 3+ . Successful emission photons of In 3+ ions are collectively absorbed by the Eu 3+ ions which lead the improvement of red emission. Optimized sensitization concentration of the In 3+ ions has been found to be 0.01 wt%. Possible energy migration phenomenon is elucidated by several fluorescent dynamics. The energy transfer process is substantiated by lifetime decay analysis and overlapped spectral studies. The Commission International de I-Eclairage chromaticity coordinates were calculated. The quantum efficiencies of the Eu 3+ ions and In 3+ ions in singly doped and co-doped polymer systems have been evaluated. From these results, these co-doped In 3+ +Eu 3+ : PVA composite polymer films might be proposed as encouraging candidates for bright red fluorescent materials for several photonic applications.