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 fundamentalin 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 devicesand solar cells, limiting their efficiency. In this work, a precise ab initio analysis of the direct Auger recombinationprocesses in both n- and p-type Si and GaAs crystals is presented. Our simulations of minority carrier Augerlifetimes rely on an accurate electronic band structure, calculated using density functional theory with theinclusion of quasiparticle corrections. The results obtained are in good agreement with experimental data forboth n-Si and p-GaAs, proving the importance of the direct Auger recombination mechanism in such systems. Onthe contrary, we show that different nonradiative recombination paths are necessary to explain the experimentalresults for both p-Si and n-GaAs.