High luminescent Eu3+ and Tb3+ doped SnO2 sol-gel derived films deposited on porous silicon

Tin oxide doped with europium (SnO2: Eu3+) or doped with europium and terbium (SnO2: (Eu3+ + Tb3+)), prepared from the sol-gel technique, is incorporated into luminescent porous silicon (PS) layers. Rutherford Backscattering (RBS) measurements reveal a complete and uniform penetration of tin, oxygen, and rare earth into the PS layer. Photoluminescence (PL) studies show that the PL peaks of rare earth are superposed to the PL band of the PS. It has been found that the recovered PL signal of the PS band is improved by adding Eu3+ to the SnO2 sol and is further improved by adding Eu3+ and Th3+. We show that a process of excitation transfer occurs from Eu3+ and Th3+ to Si nanocrystallites.