Absorption, emission and lifetimes of [2,2′ -bipyridyl]-3,3′-diol in sol-gel glasses and in polymethylmethacrylate

Correlation between photophysical properties and lasing performances of Rhodamine-19 in three types of sol–gel glass hosts

“…The value of relative efficiency is larger in dip sample (101%) than that in dope route-I (95%) and route-II (92%) sample at corresponding optimum concentration of dye. The smaller relative laser efficiency of Rh-19 in dope samples compared to the same in dip sample is because of the larger aggregation of dye in dope than in dip samples, which absorbs radiation more [42][43][44][45][46][47].…”

Ultrafast single and double proton transfer in photo-excited [2,2′-bipyridyl]-3,3′-diol

“…1). The proton transfer mechanism of BP(OH) 2 has attracted great interest in the last decade [5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. Based on the almost independence of the absorption and fluorescence band maxima of BP(OH) 2 to the polarity of the solvent and also on the basis of results from semi-empirical calculations, Bulska et al [5,6] concluded that photoexcitation of the molecule gives rise to a cooperative double proton transfer process.…”

Efficient lasing action from Rhodamine-110 (Rh-110) impregnated sol–gel silica samples prepared by dip method

“…The increase in the lifetime value of Rh-110 in sol-gel (t= 4.19 ns) compared to that in methanol (t =3.9 ns) is correlated with the high rigidity of the sol-gel matrix [16], which prevents the free intramolecular rotation of dye molecules that can result in the subsequent reduction of the nonradiative deactivation processes or quenching (S 1 -S 0 internal conversion processes) [16,23,[33][34][35][36]. In the present study, the concentration of the dye molecules was in the range of 10 15 -10 18 molecules/cm 3 .…”