Dependence of conduction-band effective mass on quaternary alloy composition of (In0.52Al0.48As)z(In0.53Ga0.47As)1−z lattice matched to InP

Cyclotron resonance measurements were carried out on high quality (In0.52Al0.48As)z(In0.53Ga0.47As)1−z thick layers grown on InP substrates by molecular beam epitaxy. The measurements were performed at 60 K and we were able to obtain the electron effective mass dependence with z in the whole range of composition 0≤z≤1. Using the band-gap values as obtained from photoluminescence measurements on the same samples at 60 K, nonparabolicity corrections were taken into account to obtain the effective mass m0* at the conduction band edge. A nonlinear variation m0* with z could be inferred from our experimental data. The expression m0*(z)/me=0.043+0.042z−0.016z2, which includes a quadratic dependence in z (or a so-called bowing parameter), gives a very good fit to our experimental data.