Electrically injected GeSn laser with stairs-structure based on SiN stressor

Abstract

After decades of advancement, optoelectronic technology has emerged as a pivotal player in various domains such as optical communication, optical interconnection, and optical computer However, the challenge of integrating optoelectronic devices with complementary metal-oxide-semiconductor (CMOS) technology remains unresolved. Germanium, with its unique band structure, can be transformed into a direct bandgap semiconductor through the introduction of tensile strain, enabling efficient light emission. This provides a solution for the development of integrated light sources based on Group IV materials. A GeSn laser with a stairs-structure based on SiN stressor is proposed in this paper. The combination of the high-stress SiN film and GeSn alloy technology allows for the modification of Ge material, enabling efficient light emission in the laser. The stairs-structure facilitates a higher tensile strain in the GeSn material. The laser utilizes an F–P resonator as the optical cavity. Through simulation experiments, the laser exhibits a threshold current density of 90kA/cm2 at room temperature, a laser wavelength of 2477 nm, and an electrical-to-optical conversion efficiency of 6.5%.