Measurement of miniband parameters of a doped superlattice by photoluminescence in high magnetic fields

TL;DR

This study uses high magnetic field photoluminescence to measure miniband parameters in a doped GaAs/AlGaAs superlattice, revealing key electronic properties and band structure details.

Contribution

It introduces a method to determine miniband width, effective mass, and band gap renormalization via magneto-photoluminescence in doped superlattices.

Findings

Measured miniband energy width.

Determined reduced effective mass of electron-hole pairs.

Observed band gap renormalization effects.

Abstract

We have studied a 50/50\AA superlattice of GaAs/Al$_{0.21}$Ga$_{0.79}$As composition, modulation-doped with Si, to produce $n=1.4\times 10^{12}$ cm$^{-2}$ electrons per superlattice period. The modulation-doping was tailored to avoid the formation of Tamm states, and photoluminescence due to interband transitions from extended superlattice states was detected. By studying the effects of a quantizing magnetic field on the superlattice photoluminescence, the miniband energy width, the reduced effective mass of the electron-hole pair, and the band gap renormalization could be deduced.