Shallow impurities in semiconductor superlattices: A fractional-dimensional space approach

A thorough detailed study of donor and acceptor properties in doped GaAs-(G a,Al)As semiconductor superlattices is performed within the fractional-dime nsional approach, in which the real anisotropic "impurity+semiconductor sup erlattice'' system is modeled through an effective isotropic environment wi th a fractional dimension. In this scheme, the fractional-dimensional param eter is chosen via an analytical procedure and involves no ansatz, and no f ittings either with experiment or with previous variational calculations. T he present fractional-dimensional calculated results for the donor and acce ptor energies in GaAs-(Ga,Al)As semiconductor superlattices are found in qu ite good agreement with previous variational calculations and available exp erimental measurements. (C) 1999 American Institute of Physics. [S0021-8979 (99)04408-4].