Determination of electron effective mass from optical transition energy in InGaAs/InAlAs quantum wells

Nonparabolic effective mass of conduction subbands in InGaAs/InAlAs quantum wells (QWs), lattice-matched to InP, was quantitatively obtained by analyzing interband-optical transition spectra. Thickness of InGaAs well was 5.3, 9.4, and 20.8nm. Thickness of InAlAs barrier was about 10nm, and each QW was independent. Excellent agreement was obtained between experimental mass and theoretical mass predicted by Kane's three-level band theory on bulk InGaAs, in a wide energy range of 0.5eV from the bandedge. Method of experimental analysis on a relation between eigen energy and effective mass was described.