Design of an electrically pumped SiGeSn/GeSn/SiGeSn double- heterostructure mid infrared laser

摘要

This paper presents the conception, modeling, and simulation of a silicon-based group-IV semiconductor injection laser diode in which the GeSn-alloy active region has a direct band gap wavelength in the 1.8 to 3.0 μm midwave infrared for 6%-12% α-Sn. The strain-free monolithic P-type semiconductor/Intrinsic semiconductor/N-type semiconductor (PIN) bulk heterostructure, grown lattice matched upon a relaxed GeSn-buffer on silicon-on-insulator, is believed to be manufacturable in a complementary metal-oxide semiconductor fab. Detailed modeling is given for the type-I band offsets, carrier lifetimes, infrared gain profile and laser threshold current density J_(th) in a Fabry-Perot cavity having 20-100 cm~(-1) loss. The laser's temperature of operation is determined by a combination of the radiative lifetime and the nonradiative lifetime due to unwanted Auger electron-hole recombination. If we keep J_(th) below 10 kA/cm~2, then we find that this laser requires cooling in the 100-200 K range, whereas J_(th) at 300 K appears to be too high for a practical device. However, the GeSn quantum-well laser diode does offer a pathway to room-temperature operation.