Nonequilibrium photocurrent modeling in resonant tunneling photodetectors

An efficient and versatile many-body nonequilibrium approach is formulated for computation of photocurrent and photoexcited properties of device structures where quantum effects dominate. This method, based on nonequilibrium Green’s function quantum transport equations, makes it possible to consider open systems of arbitrary dimensionality having complex potentials, complex geometries, and multiple terminals. In contrast to other approximate computational approaches, no a priori assumptions regarding the particular nature of the phototransitions are required (i.e., bound-to-bound, bound-to-continuum, or continuum-to-continuum). Furthermore, if desired, electron–phonon and electron–electron interactions can also be rigorously accounted for within the same formalism. In this article, the method is applied to two typical resonant-tunneling infrared detector heterostructures as examples: (1) a single-quantum-well structure, and (2) a multiperiod superlattice structure.