Radiative and nonradiative recombinations in efficient light-emitting metal-oxide-silicon tunneling diodes

The radiative and nonradiative recombinations involved in efficient light-emitting metal-oxide-silicon tunneling diodes have been studied. The radiative recombination coefficient in the silicon light-emitting diode was previously found by us to be one order of magnitude greater than that of the bulk silicon. However, the nonradiative Shockley-Read-Hall recombination still dominates the carrier recombination processes near the Si/SiO2 interface. In the present work, we show by using the voltage-dependent photoluminescence that the position of the Fermi level near the Si/SiO2 interface significantly influences the nonradiative recombination rates. The nonradiative recombination states are shown to capture electrons much more effectively. This study suggests that significant reduction in nonradiative recombination is essential for efficient light emission from silicon.