Figure 9

Direct band gaps in tensilely strained Ge. (a) Micrograph of a Ge NM bonded on a PI film. (b) Diagram showing the sample mount. (c) PL spectra of a 40-nm Ge NM at different strains. The increasing shoulder at higher wavelength reflects the lower-energy transition (black squares in (d)). (d) Symbols indicate the experimental emission energies obtained from the PL spectra of (c), plotted as a function of strain. Lines indicate the calculated Ge band gap energies versus strain. From ref[32]