INTERSUBBAND TRANSITIONS IN TRIPLE-COUPLED QUANTUM-WELLS FOR 3-COLORSINFRARED DETECTORS

We present a theoretical study of intersubband transitions in multiple -quantum-well structure, which is designed such that the chemical pote ntial lies between the third and fourth electronic energy levels. The subject structure, which may function under a fixed bias voltage, woul d allow one to observe simultaneously three intersubband transitions t hat cover different spectral wavelength regions. The current theory is based on self-consistent screened Hartree-Fock calculations for quasi particle's energies and wave functions. In this theory we include the effects of the z-dependent electron effective mass and dielectric cons tant, and the nonparabolic dispersion. The optical absorption spectra were calculated after including the depolarization and excitonlike shi fts. These spectra were investigated as a function of temperature, dop ing concentration, and bias voltage. (C) 1996 American Institute of Ph ysics.