Abstract
The authors report a spatial control of the band gap in
In
Ga
As
∕
Ga
As
quantum dots (QDs) using the combined effects of pulsed excimer laser irradiation and impurity-free dielectric cap induced intermixing technique. A large band gap shift of up to
180
meV
has been obtained under laser irradiation of
480
mJ
∕
cm
2
and 150 pulses to the
Si
O
2
capped shallow QD structure, while the nonirradiated
Si
O
2
and
Si
x
N
y
capped QDs only exhibit band gap shifts of 18 and
91
meV
, respectively.