Tensile-strained germanium microdisk electroluminescence

Opt Express. 2015 Mar 9;23(5):6722-30. doi: 10.1364/OE.23.006722.

Abstract

We report room temperature electroluminescence of tensile-strained germanium microdisks. The strain is transferred into the microdisks using silicon nitride stressors. Carrier injection is achieved with Schottky contacts on n-type doped germanium. We show that a biaxial tensile-strain up to 0.72% can be transferred by optimizing the carrier injection profile. The transferred strain is measured by the electroluminescence spectral red-shift and compared to finite element modeling. We discuss the impact of this strain level to achieve population inversion in germanium.