Structural and upconversion studies of Er3+ codoped with CdS nanoparticles in sol-gel glasses

The Er(3+) codoped with CdS nanoparticles in sol-gel glass with an average particle size of about 10 nm have been synthesized by sol-gel method. The green and red up-conversion emissions centered at about 534, 560 and 680 nm, corresponding to the (2)H(11/2)→(4)I(15/2), (4)S(3/2)→(4)I(15/2) and (4)F(9/2)→(4)I(15/2) transitions of Er(3+), respectively; were detected by a 800 nm excitation. The two-photon absorption process is involved in the green and red up-conversion emissions.