Magneto-optical properties of n-type InAsP films in ultrahigh magnetic fields*

InAsP ternary alloys have immense prospect for optoelectronic and quantum communication devices due to their variable band gap of 0.35-1.35 eV and tunability in the g-factors. We present a theoretical/experimental study of the magneto-optical properties of n-type InAs_xP_1−x films (x=0.07,0.34) in ultrahigh magnetic fields in the Faraday’s geometry at T=300 K using k.p method with modified 8-band Pidgeon-Brown model. The calculated Landau-level Fan diagram for x=0.34 suggests a near-zero g-factor. Moreover, the Field-dependent Fermi levels and the absorption coefficients show a very strong corroboration with the Cyclotron Resonance (CR) measurements, both in position and the strength. In this study, we also employed ultrafast Time Resolved Differential Reflectivity (TRDR) and ultrafast time resolved Magneto-optic Kerr Effect (MOKE) to provide information on the carrier and spin relaxation dynamics.