Fig. 1. (a), (b) TEM and HRTEM images of the GeSn/Ge MQW structure on 12-inch Si substrate. (c), (d) High-resolution XRD 2Theta-Omega curve and asymmetric (224) XRD-RSM of the as-grown sample.

Fig. 2. Band alignments of the GeSn/Ge MQW.

Fig. 3. (a) 3D schematic diagram of the GeSn/Ge MQW LED; (b) top-view microscope image of the fabricated LED; (c) I-V characteristics of the LED; (d) room temperature EL spectrum of the GeSn/Ge LED in comparison with that of Ge LED.

Fig. 4. (a) EL spectra as a function of the injected current; (b) peak position and EL integrated intensity as a function of the current density.

Fig. 5. (a) EL spectra as a function of the temperature for fixed injected current density of ∼1900  A/cm2; (b) peak position and EL integrated intensity at temperature from 300 to 460 K.

Fig. 6. (a) PL spectra as a function of temperature; (b), (c) peak position and PL integrated intensity at temperature from 220 to 460 K.