Theoretical modeling of dark current and photo-response for quantum well and quantum dot infrared detectors

Dark currents (due to direct tunneling process) and photo-response for both quantum well (QW) and quantum dot (QD) systems are calculated. A stabilization method (SM) is used to study the dynamic behavior and photo-response of an electron in an isolated QW, coupled QW or QD (with conical shape) under uniform electric field. A stabilization graph is obtained by plotting the eigenvalues of a QW or QD embedded in a confining box made of barrier material as functions of the size of the box. The eigenvalues of the system are calculated within the effective mass approximation via the Rayleigh-Ritz variational method. Density of states (DOSs) and time-dependent wave functions associated with the quasi-bound state are constructed via the SM. It is shown that the DOSs have a Lorentzian profile and the width of the Lorentzian profile gives the tunneling rate. The photo-response for QWs and conical QDs are studied and implications for device applications are discussed. (C) 2001 Elsevier Science B.V. All rights reserved.