Abstract
The
E
1 and
E
1+Δ
1 energy bands of metal–organic chemical vapor deposition grown Al
x
Ga
1−
x
As, with
x in the range 0–0.55, have been determined using photoreflectance technique. The aluminum composition for each sample was determined using the energy of the room-temperature photoluminescence compensated peak value and a suitable fundamental band gap formula. The positions of the
E
1 and
E
1+Δ
1 peaks were determined from curve-fitting an appropriate theoretical model to our experimental data by a modified downhill simplex method. Using the results, we propose new
E
1 and
E
1+Δ
1 cubic expressions as functions of the aluminum composition,
x, and compare them with the available reported expressions.