Theoretical Investigation of Tensile-Strained GeSn/SiGeSn Multiple Quantum Well Laser Wrapped in Si 3N4 Liner Stressor

Abstract

A tensile-strained GeSn/SiGeSn multiple quantum well (MQW) laser wrapped in Si3N4 liner stressor is designed and characterized theoretically. A biaxial tensile strain is introduced into the GeSn/SiGeSn MQW laser by the Si3N4 liner stressor. The boosting effects of tensile strain on the threshold current density Jth and optical gain in GeSn/SiGeSn lasers are attributed to the modulation of energy band structure and carrier distribution in the GeSn wells. Tensile-strained Ge0.90Sn0.10/Si0.161Ge0.695Sn0.144 MQW laser wrapped in 500 nm Si3N4 liner stressor achieves a Jth reduction from 476 to 168 A/cm2 and a significant enhancement of optical gain, as compared to the relaxed control device without Si3N4 . The design of GeSn/SiGeSn MQW structure wrapped in Si3N4 liner stressor provides a practical way to realize high performance GeSn based mid-infrared laser.

Keywords

• GeSn/SiGeSn
• quantum well laser
• Si3N4 liner stressor