A dependency of quantum efficiency of silicon CMOS n+pp+ LEDs on current density

A dependency of quantum efficiency of nn⁺pp⁺ silicon complementary metal-oxide-semiconductor integrated light-emitting devices on the current density through the active device areas is demonstrated. It was observed that an increase in current density from 1.6×10⁺² to 2.2×10⁺⁴ A·cm^-2 through the active regions of silicon n⁺pp⁺ light-emitting diodes results in an increase in the external quantum efficiency from 1.6×10^-7 to 5.8×10^-6 (approximately two orders of magnitude). The light intensity correspondingly increase from 10^-6 to 10^-1 W·cm^-2·mA (approximately five orders of magnitude). In our study, the highest efficiency device operate in the p-n junction reverse bias avalanche mode and utilize current density increase by means of vertical and lateral electrical field confinement at a wedge-shaped n⁺ tip placed in a region of lower doping density and opposite highly conductive p⁺ regions.