Optical properties of one- and two-component plasma in GaAs/AiGaAs n-modulation doped heterostructures

• Published in: Superlattices and microstructures 1989, Vol.6 (4), p.369-372
• Main Authors: Munnix, S., Bimberg, D., Mars, D.E., Miller, J.N., Larkins, E.C., Harris, J.S.
• Format: Article
• Language: English
• ISSN: 0749-6036; 1096-3677
• DOI: 10.1016/S0749-6036(89)80003-5

We present strong evidence for the existence of a many-body edge singularity in the luminescence spectra of GaAs/AIGaAs modulation n-doped quantum wells. The growth of thin (50 Å or less) quantum wells with high quality smooth interfaces by growth interruption, and the resulting drastic reduction of inhomogeneous broadening allows these structures to be resolved. Lineshape analysis of low-temperature, low-excitation photoluminescence spectra clearly reveals non-conservation of the wave-vector k in optical emission. Good agreement is obtained with existing theoretical lineshapes. The transition from a one component to a two component plasma is studied by means of cathodo-luminescence, where very high excitation densities (> 10 19 carriers/cm 3) can be obtained by reduction of the excitation volume at low beam acceleration voltages (∼ 0.1 m at 3 kV). Time resolved cathodoluminescence spectra reveal the dynamics of the one- to two-component plasma transition.