Abstract:
Thin films of Eu2þ doped and Dy3þ,Nd3þ co-doped Strontium Aluminate (SrAl2O4:Eu2þ,Dy3þ,Nd3þ)
phosphors were grown on Si(100) substrates by a pulsed laser deposition (PLD) technique using a
266 nm Nd:YAG pulsed laser under varying substrate temperature and the working atmosphere during
the film deposition process. The effect of substrate temperatures and argon partial pressure on the
structure and luminescence properties of the as-deposited SrAl2O4:Eu2þ,Dy3þ,Nd3þ phosphor thin films
were analysed. XRD patterns showed that with increasing substrate temperature and argon partial
pressure the peaks in the direction (220) shifted to the lower 2-theta angles. Photoluminescence (PL)
data collected in air at room temperature revealed a slight shift in the peak wavelength of the PL spectra
observed from the thin films when compared to the PL spectra of the phosphor in powder form, which is
probably due to a change in the crystal field. The PL intensity of the samples was highest for 100 °C
substrate temperature and 20 mTorr argon partial pressure. Due to this, the effect of argon partial
pressure was studied at a constant substrate temperature of 100 °C while the effect of Substrate temperatures
recorded at 20 mTorr argon pressure respectively.
Description:
The authors acknowledge with immense gratitude the South
African National Laser Centre (NLC) and the Council for Scientific
and Industrial Research (CSIR) for assisting with the PLD technique
for film ablation and deposition and also for technical, financial
and logistical support during research visits to the NLC labs. This
work is based on the research supported by the South African
Research Chairs Initiative (Grant no. 84415) of the Department of
Science and Technology, and the National Research Foundation of
South Africa and University of the Free State Cluster Fund.
