Enhanced photoluminescence of Tb3+ and Eu3+ induced by energy transfer from SnO2 and Si nanocrystallites

Terbium (Tb3+) and europium (Eu3+)-doped tin oxide (SnO2) was prepared using the sol-gel method in order to form SnO2:Tb3+ and SnO2:Eu3+ nanocomposites on monocrystalline Si wafers and porous Si (PS) substrates. The energy dispersive X-ray (EDX) analysis shows the presence of Tb inside the SnO2 layer. The high resolution transmission electron microscopy (HRTEM) observations revealed the presence of small crystallites of SnO2 where the average size ranges from 3 to 10 nm. The mechanism of rare earth excitation and emission is discussed through the absorption of SnO2 and the effect of excitation energy. SnO2:Tb3++Eu3+/Si nanocomposites are formed using the same method by doping the gel with Tb3+ and Eu3+ ions. The mechanism of emission is discussed and we show that a process of excitation transfer is performed between rare earth ions