High-Bandwidth Green Semipolar (20–21) InGaN/GaN Micro Light-Emitting Diodes for Visible Light Communication

Abstract

The light-emitting diode (LED) is among promising candidates of light sources in visible light communication (VLC); however, strong internal polarization fields in common c-plane LEDs, especially green LEDs, result in low frequency and limited transmission performance. This study aims to overcome the limited 3-dB bandwidth of long-wavelength InGaN/GaN LEDs. Thus, semipolar (20–21) micro-LEDs (μLEDs) were fabricated through several improved approaches on epitaxy and chip processes. The μLED exhibits a 525 nm peak wavelength and good polarization performance. The highest 3-dB bandwidth up to 756 MHz and 1.5 Gbit/s data rate was achieved under a current density of 2.0 kA/cm2. These results suggest a good transmission capacity of green semipolar (20–21) μLEDs in VLC applications.

Visible Light Communication System Technology Review: Devices, Architectures, and Applications

“…A µ-LED array will be prepared for monochromatic and polychromatic emission [53,54]. In this section, we review the characteristics and applications of µ-LED arrays in the field of VLC, and a brief benchmark for µ-LEDs used in VLC systems is shown in Figure 3 [42,[55][56][57][58][59][60][61][62][63][64]. To utilize µ-LEDs in a VLC system, integrating multi-color emitters on a single chip is required.…”

Recent Advances on Cyan‐Emitting (480 ≤ λ ≤ 520 nm) Metal Halide Perovskite Materials

“…[ 28 ] Therefore, the cyan‐emitting perovskite devices may be integrated into a system for underwater optical communication, such as coastal water and ocean water. [ 24–26,29–32 ] In addition, the cyan‐wavelength range is an important transition region from green to (deep) blue, whereas most of the preparation strategies of cyan‐emitting perovskites are also possible approaches for the (deep) blue‐emitting perovskites.…”

4.343-Gbit/s Green Semipolar (20-21) μ-LED for High Speed Visible Light Communication

“…To achieve high modulation bandwidth, high current densities are needed to reduce carrier lifetime; however, high current density will reduce the LED internal quantum efficiency (IQE) due to the efficiency droop [17]. LED grown on nonpolar or semipolar orientations could offer higher modulation bandwidth owing to the large overlap of electron-hole wavefunction with shortened carrier lifetimes [18,19]. It is reported that semipolar LED has small efficiency droop due to a higher percentage of radiative to Auger recombination coefficients [20].…”