Superinjection in single-photon emitting diamond diodes

Practical applications exploiting the quantum nature of light require efficient and bright room-temperature single-photon sources. At present, color centers in diamond are considered to be the most promising candidates. However, their efficient electrical excitation is challenging due to the inability to create a high density of free electrons in diamond. In this work, we predict the superinjection effect in diamond homojunction p-i-n diodes, which enables to inject up to four orders of magnitude more electrons into the i-region than the doping of the n-type region allows. Despite that the superinjection effect is known to be a unique feature of semiconductor heterostructures, we demonstrate for the first time that this effect can also be observed in homojunction diamond diodes, giving the possibility to overcome the doping problem and design bright electrically driven single-photon sources.