We propose that short-period doping superlattices are suitable for the enhancement of a third-order susceptibility arising from free carriers in nonparabolic energy subbands. The inherent advantage lies in the ability to simply engineer the superlattice potential profile, yielding control of miniband energy dispersion. We consider short-period GaAs doping superlattices composed of uniformly doped donor and acceptor layers, and planar-doped n- and p-type monolayers separated by intrinsic regions. Calculations of the electronic structure of compensated and n-type noncompensated n-i-p-i superlattices incorporating miniband dispersion at nonzero temperature are reported. We show that small modulations of the superlattice potential lead to large subband nonparabolicities and we calculate a twentyfold improvement in the third-order susceptibility over bulk GaAs at room temperature, comparable to that predicted for GaAs/AlGaAs compositional superlattices.
ASJC Scopus subject areas
- Physics and Astronomy(all)