The improvement in modulation speed of GaN-based Green light-emitting diode (LED) by use of n-type barrier doping for plastic optical fiber (POF) communication

We demonstrate a high-speed GaN-based light-emitting diode at a wavelength of around 500 nm for the application to plastic optical fiber communication. By use of the n-type doping in the GaN barrier layers of the In
_x
Ga
_1-x
N-GaN-based multiple-quantum-well (MQW), superior performance of modulation-speed (120 versus 40 MHz) and output power to the undoped control under the same bias current has been observed. According to the measured electrical-to-optical bandwidths and extracted RC-limited bandwidths of both devices, the superior speed performance can be attributed to higher electron/hole radiative recombination rate in the n-doped MQW than that of undoped MQW