Luminescence properties of SrS:Ce3+

Abstract

SrS:Ce is an intensively investigated phosphor due to its blue-green electroluminescence, which shows efficient blue emission after filtering. Recently reported devices based on this material have demonstrated a luminous efficiency of 1.6 lm/W. The luminescence properties of SrS:Ce,X (X=Na or Cl) have been studied on powders and thin films. It is shown that a high density of traps in SrS:Ce,X occurs. The interaction of Ce3+ with traps gives rise to a phosphorescence. An energy transfer from Ce3+ to traps is responsible for an observed luminescence quenching in the presence of high electric fields. Moreover, the traps are electrically active and are involved in the electroluminescence process. The observed energy transfer is proposed to be the dominant excitation mechanism of Ce3+ in electroluminescence. It is demonstrated for thin films that the defect density increases with doping; therefore, the luminescence yield is already limited at doping concentrations below the onset of the concentration quenching. Thus, the prepared SrS:Ce,Cl thin films show a lower photoluminescence yield than powders. It is concluded that an undisturbed Ce incorporation into SrS thin films has not been achieved so far, although high electroluminescence efficiencies (1.6 lm/W) have been obtained.

Thermoluminescence response and trap parameters determination of gamma exposed Ce doped SrS nanostructures

“…1). High doping shows the well known concentration quenching of the luminescence due to an enhanced interaction between the centres and the disturbed lattice periodicity [15].…”

Optical properties of Ce3+-doped KLuS2 phosphor

“…A double insulated CaS:Ce thin-film electroluminescent (EL) device emitting a bright green EL due to the Ce 3 þ luminescent centre has been reported [7]. SrS doped by Ce 3 þ and co-doped by Pb 2 þ or Cl À , Na þ also gained attention mainly due to possibility of being used as thin films in electroluminescence devices [8][9][10]. Codoping of SrS:Ce by other RE 3 þ ions and their impact on the transient emission processes are discussed in [11].…”

Blue shift in band gap and photoluminescence of pulsed laser deposited SrS:Ce/quartz thin film nanophosphors

“…The blue shift in PL has been observed for SrS:Ce thin film nanophosphors, but the PL output was found to be almost six times lower than that from the powder phosphors. Huttl et al [27] have also reported that PL yield for SrS:Ce,Cl thin films is around five times lower than that for powders.…”