Auger recombination in Si and GaAs semiconductors: Ab initio results

A detailed description, at the atomistic scale, of the dynamics of excess electrons and holes is fundamental in order to improve the performance of many optoelectronic devices. Among all recombination processes, nonradiative decay paths play a fundamental role in most semiconductor devices, such as optoelectronic devices and solar cells, limiting their efficiency. In this work, a precise ab initio analysis of the direct Auger recombination processes in both n- and p-type Si and GaAs crystals is presented. Our simulations of minority carrier Auger lifetimes rely on an accurate electronic band structure, calculated using density functional theory with the inclusion of quasiparticle corrections. The results obtained are in good agreement with experimental data for both n-Si and p-GaAs, proving the importance of the direct Auger recombination mechanism in such systems. On the contrary, we show that different nonradiative recombination paths are necessary to explain the experimental results for both p-Si and n-GaAs.