Simultaneous magneto-electro-optical measurements in modulation-doped quantum well: An investigation on magneto-photoluminescence intensity oscillations

Abstract

Quantum Hall and magneto-photoluminescence (magneto-PL) measurements are simultaneously performed on a GaAs quantum well to establish a detailed correlation between magneto-optical and magneto-transport properties of charge carriers. The longitudinal/transverse magneto-resistances under dark and illuminated conditions provide insight into an electron–electron interaction that pushes charge carriers toward the heterointerfaces. It is observed that photogenerated holes screen this interaction potential and annihilate the accumulation of electrons in the ground energy state. In this process, carriers from excited states are redistributed in lower energy sub-bands, which affect the quantum scattering time of carriers. In particular, the scattering time associated with an excited state is significantly reduced as compared to the ground state. Under this condition, the redistribution of charges among Landau states is probed by the magneto-PL measurements. Also, magneto-PL spectroscopy is used to estimate recombination time, carrier occupancy in Landau states, and Fermi energy as a function of a magnetic field. In our previous work [J. Lumin. 206, 342 (2019)], it was demonstrated that a variation in the strength/orientation of a magnetic field can control the recombination and separation of charges, where the PL spectra under a parallel magnetic field help to acquire anisotropic properties of charge carriers. Here, a similar method is used to estimate the anisotropic properties of carriers under an external electric field and then correlated with that obtained from quantum Hall measurements during illumination. Furthermore, a new method to record magneto-PL intensity oscillations is described, which can be used to realize magneto-optical properties of carriers without any line-shape fitting procedure.