Time-resolved electroluminescence of bulk Ge at room temperature

Time-resolved spectroscopy of bulk Ge at room temperature allows to differentiate direct-gap electroluminescence (EL) from indirect-gap EL. The results indicate that there exists strong coupling between the eight-fold indirect L-valleys and the zone-center Gamma-valley due to intervalley phonon scattering at room temperature in the absence of built-in strain. Pulse modulation of EL at 10-MHz is consistent with the relevance of the direct-gap transition. (C) 2013 American Institute of Physics. [http://dx.doi.org/10.1063/1.4789511]