 Trap-assisted electron-hole recombination

A localized electronic defect can capture a conduction electron and subsequently an electron hole, or the reverse sequence, returning to its original charge state. Energy is transferred to the lattice rather than an emitted photon. The two-step process can remove an electron-hole pair even when direct band-to-band photon emission is inefficient. Its rate depends on trap density, occupation and both capture rates; a single trapping event is not necessarily completed recombination.