3. Results and discussion
The analysis of UV–VIS spectra of SrO QDs shown in Fig. 1 was
carried out with a view to explore their optical properties.
Fig. 1 shows that the% transmission is higher on lower wavelength
side. It was seen that the strongest absorption appears at
wavelength 203 nm. At lower wavelengths edge absorption represents
the quantum confinement effect present in the synthesized
SrO QDs. Many applications of the materials depend upon its direct
and indirect band gap values. The relation between absorption
coefficient (a) and incident photon energy (hm) can be expressed
as Eq. (1).
a ¼ Aðhv EgÞ
n
hv ð1Þ
where A is constant and Eg is the band gap of the material. The
exponent n depends on the type of the transition, its value is 1
for direct band gap and 2 for indirect band gap. The exact values