[17a-Z10-1~10] 3.15 Silicon photonics and integrated photonics

[17a-Z10-4] Temperature dependence of direct bandgap in strained Ge layer on Si

〇Shinjiro Kenmotsu¹, Junichi Fujikata², Yasuhiko Ishikawa¹ (1.Toyohashi Univ. Tech., 2.PETRA)

Keywords:Germanium, Photonic Devices

Operating wavelength of Ge photonic device is dependent on the fundamental absorption edge of the Ge layer, i.e., the direct bandgap, and its temperature dependence is important for the operating characteristics. The temperature dependence of the direct gap is investigated for the strained Ge layer epitaxially grown on a bonded silicon-on-quartz (SOQ) wafer. Similar to the unstrained bulk Ge, the direct gap shows a narrowing with increasing the temperature. The rate of change is close to that of Varshni's empirical formula.