Theoretical Investigation of Strain-Adjustable Ge0.92Sn0.08 Light-Emitting Diodes With Giant Magnetostrictive Stressor for Short-Wave Infrared Light Source

A new idea was provided by the group-IV GeSn alloys for short-wave infrared light source compatible with CMOS due to the low cost integrated on the Si platform and can be transformed into direct bandgap alloy. More than 7.1% Sn content or strain engineering is used to achieve the direct bandgap GeSn semiconductors and enhance the luminous efficiency of GeSn light-emitting devices. We theoretically investigate a strain-adjustable GeSn light-emitting diode with the giant magnetostrictive stressor. A 0∼0.11% adjustable uniaxial tensile strain is introduced into Ge
_0.92
Sn
_0.08
LED by adjusting the external magnetic field. A continuously adjustable bandgap from 0.543 eV to 0.475 eV of the Ge
_0.92
Sn
_0.08
alloy is achieved in the magnetic field intensity range of 0∼240 kA/m, and the spontaneous emission rate of the strained LED is enhanced about 3.63 times compared with the relaxed device. Besides, an adjustable range of luminous peak is achieved from 2.18 μm to 2.46 μm, which can promote the application of GeSn light source for magnetic field detection and photo-communication in short-wave infrared.