Nitride-based light-emitter and photodiode dual function devices with InGaN/GaN multiple quantum dot structures

In this work, a light-emitter with InGaN/GaN multiple quantum dot structures has been employed for a dual function device exhibiting the photodiode (PD) characteristics in reverse bias. The turn-on voltage in forward bias and the breakdown voltage in reverse bias were 3 and −13.5 V, respectively. Furthermore, with an incident wavelength of 350 nm and 3 V applied bias, the maximum responsivity of this device was 0.13 A/W. It was also found that the responsivity was nearly a constant from 390 to 440 nm. Thus, one can easily integrate PDs with LEDs using the same epistructure to realize a GaN-based optoelectronic integrated circuit.