Photoelectric Characteristics of Non-electric Contact GaN-based Micro-LED Device

Abstract：In this paper，non-electrical contact(NEC) GaN-based Micro-LED devices were prepared by metal organic chemical vapor deposition(MOCVD)and atomic layer deposition(ALD)because a series of problems would emerge，including mass transfer，bonding，and high-quality contact between chips and driving electrodes as the LED chip size is further decreased.We investigated the photoelectric characteristics of NEC Micro-LED devices，such as the current-voltage (I-V)，luminance-frequency(L-F)，luminescence delay and impedance-frequency(I-F) characteristics，and the working mechanism of the device is also analyzed.These experimental results indicate that the current of the NEC Micro-LED device increases with the increase of the frequency and I-V curves have linear relationships under the role of the alternating-current drive.At the driving signal of 20V pp ，the luminances of the NEC Micro-LED device first increase and then fall with the gradual increases of the frequencies.When the frequency is 25 MHz，the luminance of NEC Micro-LED device reaches to be the maximum.Moreover，the luminescence peak lags behind the current peak， indicating that the luminescence of the device is delayed.Besides，the equivalent impedance of the