Trap-assisted Auger-Meitner recombination from first principles

Trap-assisted nonradiative recombination is a key mechanism limiting the efficiency of optoelectronic devices such as light emitting diodes. Trap-assisted recombination via multiphonon emission (MPE) has been studied from first principles; its rate was found to become negligibly low in materials with band gaps larger than about 2.5 eV, and it cannot explain the experimentally measured trap-assisted recombination rates in such materials. We propose that trap-assisted Auger-Meitner (TAAM) recombination can account for the experimental observations. We have developed a practical first-principles methodology to calculate the TAAM rate in semiconductors. As a case study, we applied our formalism to a calcium substitutional impurity in InGaN. We found that for band gaps larger than 2.5 eV, the combination of hole capture by MPE and electron capture by TAAM results in recombination rates orders of magnitude larger than the recombination rate governed by MPE alone. Our computational formalism is general and can be applied to any defect or impurity in any semiconducting or insulating material.