Material configurations for n-type silicon-based terahertz quantum cascade lasers

Abstract

Silicon-based quantum cascade lasers (QCLs) offer the prospect of integrating coherent THz radiation sources with silicon microelectronics. Theoretical studies have proposed a variety of n-type SiGe-based heterostructures as design candidates, however the optimal material configuration remains unclear. In this work, an optimization algorithm is used to design equivalent THz QCLs in three recently-proposed configurations [(001) Ge/GeSi, (001) Si/SiGe and (111) Si/SiGe], with emission frequencies of 3 and 4 THz. A systematic comparison of the electronic and optical properties is presented. A semi-classical electron transport simulation is used to model the charge carrier dynamics and calculate the peak gain, the corresponding current density and the maximum operating temperature. It is shown that (001) Ge/GeSi structures yield the best simulated performance at both emission frequencies.

9 pages, 7 figures

References in corpus (7)

• Intersubband absorption linewidth in GaAs quantum wells due to scattering by interface roughness, phonons, alloy disorder, and impurities
• Nonequilibrium Green's function theory for transport and gain properties of quantum cascade structures
• Coherence of resonant-tunneling transport in terahertz quantum-cascade lasers
• Generalized effective mass approach for cubic semiconductor n-MOSFETs on arbitrarily oriented wafers
• Intersubband carrier scattering in n- and p-Si/SiGe quantum wells with diffuse interfaces
• Theory and design of quantum cascade lasers in (111) n-type Si/SiGe
• Intervalley splitting and intersubband transitions in n-type Si/SiGe quantum wells: pseudopotential vs. effective mass calculation

Cited by in corpus (4)

• Room temperature operation of n-type Ge/SiGe terahertz quantum cascade lasers predicted by non-equilibrium Green's functions
• An extended density matrix model applied to silicon-based terahertz quantum cascade lasers
• THz intersubband electroluminescence from n-type Ge/SiGe quantum cascade structures
• Intersubband transition engineering in the conduction band of asymmetric coupled Ge/SiGe quantum wells