Extended Data Fig. 10: External radiative efficiency.
From: Direct-bandgap emission from hexagonal Ge and SiGe alloys
a, Integrated photoluminescence intensities of hex-SiGe in comparison with high-quality InGaAs/InP multiple quantum well (QW) samples as measured in a micro-photoluminescence setup using 1,030-nm wavelength, 125-pJ pulses. The photoluminescence intensities of both the MQWs and the hex-SiGe wires were corrected using their respective absorption and emission efficiencies as given in the Methods section ‘External radiative efficiency of hex-SiGe’. b, A cross-sectional schematic demonstrating the layer structure of the InGaAs/InP multiple QW sample, showing a total absorption thickness of 625 nm. The bandgap wavelengths (WL) of the layers that are not lattice-matched to InP are indicated. c, A schematic illustration of the geometry of our horizontally oriented hex-SiGe nanowire, showing the emission into a NA = 0.48 cassegrain objective with a NA = 0.22 obscurity. The polarization of the emitted light is indicated as V and H for vertical and horizontal, respectively.
