Room temperature direct-bandgap electroluminescence from a horizontal Ge ridge waveguide on Si
He Chao, Liu Zhi, Cheng Bu-Wen†, 
(a) Direct-bandgap EL spectra of edge emission under different currents. The length of Ge waveguide is 270 μm. (b) Relationship between integral EL intensity and current density, which is characterized by
