Description

In common light-emitting diodes (LED), nonradiative recombination processes limit lighting efficiency and converts electrical energy into heat. We have found by calculations that trap-assisted Auger-Meitner recombination in blue LEDs can be the dominating mechanism in limiting lighting efficiency.

The image shows how the electrons behave in a trap-assisted Auger-Meitner (TAAM) recombination happened in a Ca substitutional impurity in GaN. The TAAM is one of the nonradiative recombination processes assisted by trap states involving an electron-hole recombination event with the energy transferred to another free carrier. The red balls are electrons, with trajectory shown by the yellow glossing tails, and the purple spindles denote the wavefunction of the hole state induced by the Ca impurity. The blue, green, and brown balls denote Ca, Ga, and N atoms, respectively. The energy coming from the recombination of the lower electron and the hole is transferred to the higher electron. The atomic structure is the accurately calculated structure in a real Ca impurity system in GaN.