Effects of extreme disorder on electronic properties in δ-doped semiconductor microstructures—a realistic computer simulation
✍ Scribed by C. Metzner; M. Hofmann; G.H. Döhler
- Publisher
- Elsevier Science
- Year
- 1999
- Tongue
- English
- Weight
- 79 KB
- Volume
- 25
- Category
- Article
- ISSN
- 0749-6036
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✦ Synopsis
Impurity induced disorder is a key feature of strongly doped semiconductor microstructures. We present a theoretical approach which allows the realistic and efficient calculation of localized quantum states in layered, delta-doped systems and the resulting properties of the quasi-2D multisubband electron/hole gas. The random Coulomb potential is directly computed from the impurity distribution without any simplifying assumptions. Electronelectron interaction is treated self-consistently on the Hartree level. The extreme cases of the doping superlattice (strong disorder) and the modulation doped quantum well (weak disorder) are studied as example device structures. Intersubband absorption spectra are then calculated for both types of systems and studied as a function of the electron filling factor. Striking differences are found between the linewidths of potential fluctuations and absorption spectra. These results are explained on the basis of system geometry, nonlinear screening and intersubband correlations. Finally, we discuss possible future applications and extensions of the method.