Theory and design of quantum cascade lasers in (111) n-type Si/SiGe

Abstract

Although most work toward the realization of group IV quantum cascade lasers (QCLs) has focused on valence-band transitions, there are many desirable properties associated with the conduction band. We show that the commonly cited shortcomings of n-type Si/SiGe heterostructures can be overcome by moving to the (111) growth direction. Specifically, a large band offset and low effective mass are achievable and subband degeneracy is preserved. We predict net gain up to lattice temperatures of 90 K in a bound-to-continuum QCL with a double-metal waveguide, and show that a Ge interdiffusion length of at least 8 angstroms across interfaces is tolerable.

7 pages, 6 figures

References in corpus (3)

• Valley Splitting Theory of SiGe/Si/SiGe Quantum Wells
• Intersubband carrier scattering in n- and p-Si/SiGe quantum wells with diffuse interfaces
• 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
• Optoelectronic device simulations based on macroscopic Maxwell-Bloch equations
• An extended density matrix model applied to silicon-based terahertz quantum cascade lasers
• Material configurations for n-type silicon-based terahertz quantum cascade lasers