Tuning luminescence of 3d transition-metal doped quantum particles: Ni+2: CdS and Fe+3: CdS

The room-temperature photoluminescence of Cd1-xMxS (M=Ni, Fe) nanoparticles were investigated. Compared with the photoluminescence of CdS which peaks at 475 nm, the photoemission of CdS:Fe nanoparticles was peaking at 537 nm because of Fe acting as luminescent centers. On the other hand, the green emission (503 nm) of CdS:Ni attributed to the T-1(2g)(D) -> (3)A(2g)(F) raditive transition. With the increase of the Ni+2 concentration, photoluminescence intensity is increased while by Fe replacement with Cd ions, PL intensity is decreased. Relative to bulk crystals, due to the quantum confinement effect the band gap of CdS clusters is significantly blue-shifted with decreasing cluster size. CdS nanoclusters present a mixed hexagonal/cubic structure and with increasing doping concentration the peaks position of doped CdS shifts to higher angle.