Temperature effect of magneto-photoluminescence in InGaAs/InAlAs quantum wells: application of band theory to nonparabolic conduction subband
Interband magneto-photoluminescence (MPL) spectra in n-type InGaAs/InAlAs quantum wells (QWs) lattice-matched to InP were measured between 1.4 and 275 K. From a fan chart of MPL peak energy vs. magnetic field, assignment of Landau levels (LLs) associated with conduction subband (CS) was made consistently. Two series of LL peak energies with different Landau quantum number was subtracted to cancel the effects of complex valence subband states and bandgap renormalization, etc. The energy difference of two CS LL peak series in the MPL fan chart, between Landau quantum number 0 and 1, did not agree with the measured cyclotron resonance (CR) energy or the related theoretical CS LL energy difference. The difference was 610 meV at 1.4 K near 10 T. Temperature dependence of the difference of CS LL peak energies was studied and the difference tended to diminish at 175275 K. The behavior suggested that the quantity was the difference of magneto-exciton binding energy and that the exciton states were merged into LLs at higher temperature. A band parameter, Ep, in nonparabolic band theory was discussed.
magneto-photoluminescence landau level magneto-exciton multi-quantum well