QUANTUM EFFECTS OF POTENTIAL FLUCTUATIONS IN GAAS DELTA-DOPING SUPERLATTICES

The electronic and optical properties of delta-doping n-i-p-i superlat tices are strongly influenced by the random distribution of donors and accepters within the doping layers. A Monte-Carlo method is applied t o investigate the resulting potential fluctuations and local changes o f energy levels and wavefunctions. We study disorder effects on the de nsity of states, the capacitance and the intraband absorption coeffici ent as a function of excitation level. In addition, the luminescence s pectra are calculated and compared to electroluminescence measurements . Excellent agreement is achieved without using any fitting parameters , if the local wavefunction shrinkage of the tail states is included. While contributions of different subbands cannot be resolved in the lu minescence, the simulation of conduction band (CB) intraband absorptio n confirms that this is possible using resonant Raman scattering.