Electrically Injected GeSn Lasers towards Room Temperature
Use of group IV materials for semiconductors offers many benefits compared to traditional group III-V materials. Germanium tin (GeSn) in particular has a direct bandgap above 8% Sn composition, making it ideal for use in optoelectronic devices. GeSn is also complementary metal-oxide-semiconductor (CMOS) compatible and has potential applications in infrared imaging and light detection and ranging (LIDAR) technology. However, electrically injected GeSn lasers have not yet been extensively researched. The operating temperatures for such devices are low, with the world record highest temperature at 110 K. Higher operating temperatures are desired to increase use in applications. A PIN-doped GeSn wafer was prepared by chemical vapor deposition (CVD) and wet etching. Electrodes were deposited and wire bonded to an Si carrier chip to form a PIN-diode. The sample was electrically injected using a pulsed voltage source. The electroluminescence (EL) spectra and light output versus current (LI) curves were measured. The device successfully lased with a wavelength of 2688 nm at the maximum temperature of 135 K. This beat the previous world record operating temperature by 25 K. The threshold current density was 701 A/cm2 at 77 K and 2813 A/cm2 at 135 K. Alterations in material growth and device structure need to be studied in order to further increase operating temperature to room temperature.
Shui-Qing Yu, University of Arkansas
Primary Advisor's Department
Electrical and Computer Engineering
Stander Symposium project, School of Engineering
United Nations Sustainable Development Goals
Affordable and Clean Energy
"Electrically Injected GeSn Lasers towards Room Temperature" (2022). Stander Symposium Projects. 2736.