Rapid color-switching micro-LEDs from silicon MIS diodes

A micro-LED on silicon that can switch between visible and infrared emission is demonstrated. Switching rates of up to 50 MHz were measured, limited in part by our pulse generator and measurement system. Modeling of the emission dynamics suggests that modulation rates for the visible and infrared bands can approach higher frequencies with a significant offset. The fabrication of these devices is compatible with CMOS post-processing conditions. A current limitation is the low external efficiency due in part to the metal contacts and internal reflection.