Year: 2009
Type: article
Abstract: We report what we believe to be the first demonstration of direct bandgap electroluminescence (EL) from Ge/Si heterojunction light-emitting diodes (LEDs) at room temperature. In-plane biaxial tensile strain is used to engineer the band structure of Ge to enhance the direct gap luminescence efficiency by increasing the injected electron population in the direct Gamma valley. Room-temperature EL is observed at the direct gap energy from a Ge/Si p-i-n diode exhibiting the same characteristics of the direct gap photoluminescence of Ge. The integral direct gap EL intensity increases superlinearly with electrical current owing to an indirect valley filling effect. These results indicate a promising future of tensile-strained Ge-on-Si for electrically pumped, monolithically integrated light emitters on Si.
Source: Optics Letters
DOI: 10.1364/ol.34.001198
Institution: Massachusetts Institute of Technology
Language: English
Topic: Photonic and Optical Devices
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: green
OpenAlex ID: W2114990901