Fast switching of light-emitting diodes

We have proposed a method of increasing the switching speed of a light-emitting diode by controlling the voltage across the device rather than the current through it. While the speed of conventional current-control methods is limited by the recombination processes in the active region, with their characteristic time being of the order of several nanoseconds, we have shown both analytically and numerically, that the characteristic time of the voltage-control method can be two orders of magnitude smaller. Such a speed is provided by a large pulsed current that rapidly removes excessive carriers from the active region if the device is being switched off, and injects them into the active region if the device is being switched on.