Strain-Engineered Germanium Microbridge LED With Silicon Nitride Stressor

Abstract

Germanium (Ge) has garnered significant attention in the field of silicon-based monolithic light sources as an attractive material. Silicon nitride is widely used in optoelectronic devices due to its excellent optical properties. By using silicon nitride as a stressor to introduce tensile strain into Ge, the band structure of Ge can be tuned, enhancing the radiative recombination of direct bandgap emission. A LED with silicon nitride as a stressor is proposed in this paper. Simulation results demonstrate that the device has been introduced to a 3% uniaxial tensile strain, resulting in peak electroluminescence at 1986 nm and a maximum electro-optical conversion efficiency of 1.94%, indicating excellent performance in the short infrared wavelength range. This work provides a method for achieving more efficient silicon-based group IV light sources.