Ensemble Monte Carlo modeling of quantum cascade detectors

Abstract

We present a method to perform accurate and efficient simulations of photovoltaic quantum cascade detector (QCD) structures based on the ensemble Monte Carlo (EMC) approach. Since the photocurrent is typically orders of magnitude smaller than the pump current in a quantum cascade laser (QCL), a direct application of QCL simulation techniques is not sufficiently accurate. We demonstrate that by exploiting thermodynamic equilibrium relations for the electron populations and scattering rates, the EMC method can be adapted to yield reliable results for the essential QCD figures of merit, such as responsivity and specific detectivity. The modeling approach is validated against available experimental results for various mid-infrared and terahertz QCD designs and furthermore compared to simulations based on the non-equilibrium Green’s function method.

Multi-Domain Modeling of Free-Running Harmonic Frequency Comb Formation in Terahertz Quantum Cascade Lasers

“…To model the light-matter interaction in a THz HFC QCL, our open-source Maxwell-DM tool mbsolve is used [43], [44], [64]. All input parameters required for a complete description of the quantum system are extracted from our in-house open-source monacoQC framework [44], [65], a quantum cascade (QC) device simulation tool [66]- [68]. In the following, the monacoQC framework with the base library for QC device specifications and the charge carrier transport simulation results are explained in more detail.…”

Multi-Domain Modeling of Free-Running Harmonic Frequency Comb Formation in Terahertz Quantum Cascade Lasers

“…To model the light-matter interaction in a THz HFC QCL, our open-source Maxwell-DM tool mbsolve is used [43], [44], [64]. All input parameters required for a complete description of the quantum system are extracted from our in-house open-source monacoQC framework [44], [65], a quantum cascade (QC) device simulation tool [66]- [68]. In the following, the monacoQC framework with the base library for QC device specifications and the charge carrier transport simulation results are explained in more detail.…”

Electrical flicker-noise analysis based on trapping and de-trapping model in quantum-cascade detectors

“…[1,2,6] Various design concepts of the active region have been proposed with the aim of improving the responsivity and operation temperature, and bandwidth of the response spectrum. [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21] Owing to progress in the design of the active region, as well as their low-noise property with bias-free photovoltaic operation, the noise-equivalent power of QC detectors compares favorably with the other uncooled IR detectors, such as mercury-cadmium-telluride detectors. [22,23] In addition, highspeed operation with a response time on the order of picoseconds has been demonstrated in mid-IR QC detectors for the detection of a high-frequency heterodyne beat signal, [24,25] microwave rectification, [26] and the observation of an impulse response of a femto-second optical pulse.…”