Photoexcited Quantum Wells: Nonlinear Screening, Bistability, and NegativeDifferential Capacitance

摘要

The dielectric response of an electron-hole plasma confined to a slab iscalculated within the Hartree approximation for electric fields perpendicular to the slab walls. The results are used to infer the capacitance behavior of photoexcited quantum-well structures under different rate conditions. Case studies show that nonlinearities in the carrier-density dependence of the energy spectrum and scattering times can lead to bistability and negative differential capacitance. Keywords: Quantum wells; Instability; Capacitance; Dielectric response; Nonlinear screening; Reprints. (jhd)