Optically Detected Far-Infrared Magnetoabsorption in InGaAs

InGaAs epitaxial layers lattice-matched to InP substrates are studied by photoluminescence measurements modulated by far-infrared radiation under the condition of cyclotron resonance or impurity cyclotron resonance. Based on the experimental results, the ionization energy of shallow donors is estimated to be 2.3 meV, which is lower than the value of 3.0 meV obtained from the effective mass approximation. In order to explain the difference between the two values, we propose a model of the existence of a Ga-rich region in samples. In addition to electron cyclotron resonance, hole cyclotron resonance is observed. The effective masses of electron and light hole are estimated to be 0.041m 0 and 0.051m 0 , respectively.