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

A. Valavanis, L. Lever, C. A. Evans, Z. Ikonić, R. W. Kelsall
2008 Physical Review B  
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
more » ... mperatures 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.
doi:10.1103/physrevb.78.035420 fatcat:qmnsqxtz2basljdpbujlijjcbq