Effect of the dopant location and the number of Bragg mirrors on the performance of superlattice infrared photodetectors

We have investigated the influence of the position of the dopants and the number of Bragg mirrors in the confinement of localized states in the continuum of a InGaAs/InAlAs superlattice with a structural defect. The potential profile of the conduction band of the superlattice was determined by self-consistently solving the Schrödinger-Poisson equations. The influence of these parameters was analyzed by the oscillator strength of the optical transition between the ground state and the first localized state in the continuum. The best location for the dopants is in the structural defect quantum well, for which an oscillator strength of 0.25 was obtained. It is found that two Bragg mirrors are enough to confine the first localized state in the continuum without decreasing the oscillator strength of the optical transition from the ground state.