Optical properties of an ensemble of G-centers in silicon

Abstract

We addressed the carrier dynamics in so-called G-centers in silicon (consisting of substitutional-interstitial carbon pairs interacting with interstitial silicons) obtained via ion implantation into a silicon-on-insulator wafer. We performed detailed photoluminescence experiments as a function of excitation energy, incident power, irradiation fluence, and temperature in order to study the impact of radiative and nonradiative recombination channels on the spectrum, yield, and lifetime of G-centers. In the framework of the Huang-Rhys theory with nonperturbative calculations of the acoustic phonon sidebands, we reach an estimation of $1.6\ifmmode\pm\else\textpm\fi{}0.1\phantom{\rule{4pt}{0ex}}\AA{}$ for the spatial extension of the electronic wave function in the G-center. The radiative recombination time measured at low temperature lies in the 6 ns range. The estimation of both radiative and nonradiative recombination rates as a function of temperature further demonstrates a constant radiative lifetime.