Enhanced stokes shift of S 2 → S 0 emission and structural investigations of Sn(IV)Porphyrins doped hybrid borate glasses

Abstract

In the present study, we report our results on Sn(IV)TPP and its derivatives doped hybrid borate glasses. The photophysical and structure of Sn(IV)Porphyrins in borate glass matrix was studied through micro-Raman, optical absorption, steady state and time resolved fluorescence emission techniques. The optical absorption spectrum shows red shift in Soret band and change in the intensity of Q-bands. Upon exposure to UV light at 260 nm, the glass samples exhibit strong blue emission and red emission at 365 nm. Steady state fluorescence emission spectrum of hybrid glasses exhibits dual emission bands originating from the S 2 → S 0 and S 1 → S 0 states. The appearance of large stokes shift (Δ υ), enhanced S 2 → S 0 emission at ∼482 nm and excitation dependent of S 1 → S 0 emission indicates that the structure of Sn(IV)Porphyrins were inherently modified in the borate glass matrix. Time resolved fluorescence of S 2 → S 0 emission was found to be in the range of 0.23–0.36 ns, S 1 → S 0 emission shows 1.23–1.57 ns and 9.12–9.63 ns, respectively. The results obtained in glass matrix were correlated with solution medium and the possible structures were investigated.