Effective sensitization of Eu3+ and energy transfer in Sm3+/Eu3+ co-doped ZPBT glasses for CuPc based solar cell and w-LED applications

Sm3+/Eu3+ co-doped transparent Zinc Phosphate Barium Titanate (ZPBT) glasses have been successfully prepared via melt quenching technique. The photoluminescence properties and energy transfer mechanisms of these glasses were investigated in detail. The addition of Sm3+ as sensitizer expanded the excitation spectrum of Eu3+ in the Sm3+/Eu3+co-doped ZPBT glasses. The mechanism for energy transfer from Sm3+ to Eu3+ was dipole-dipole in nature, which was confirmed by Dexter energy transfer formula and Reisfeld's theory on emission spectra and Inokuti Hirayama (I-H) model on decay curves. The Sm3+/Eu3+ co-doped ZPBT glasses reveal the capability to down-convert the n-UV and blue wavelength photons located in the weakest absorption of copper phthalocyanine (CuPc), to red-emitting photons in the optimal absorption of CuPc. The evaluated CIE chromaticity coordinates for the glasses move towards the red region with the increase in Eu3+ concentration under n-UV excitation wavelength. The above-mentioned results imply that the Sm3+/Eu3+ co-doped ZPBT glasses are the potential candidate for applications in CuPc based solar cells and w-LEDs.