A THEORETICAL RESONANT-TUNNELING APPROACH TO ELECTRIC-FIELD EFFECTS IN QUASI-PERIODIC FIBONACCI GAAS-(GA,AL)AS SEMICONDUCTOR SUPERLATTICES

A theoretical resonant-tunnelling approach is used in a detailed study of the electronic and transmission properties of quasiperiodic Fibona cci GaAs-(Ga,Al)As semiconductor superlattices, under applied electric fields. The theoretical scheme is based upon an exact solution of the corresponding Schroedinger equations in different wells and barriers, through the use of Airy functions, and a transfer-matrix technique. T he calculated quasibound resonant energies agree quite well with previ ous theoretical parameter-based results within a tight-binding scheme, in the particular case of isolated Fibonacci building blocks. Theoret ical resonant-tunnelling results for S-4 and S-5 generations of the qu asiperiodic Fibonacci superlattice reveal the occurrence of anticrossi ngs of the resonant levels with applied electric fields, together with the conduction-and valence-level wave function localization propertie s and electric-field-induced migration to specific regions of the semi conductor quasiperiodic heterostructure. Finally, theoretical resonant -tunnelling calculations for the interband transition energies are sho wn to be in quite good quantitative agreement with previously reported experimental photocurrent measurements.