Influence of Current Density and Capacitance on the Bandwidth of VLC LED

High-Speed Visible Light Communication Based on a III-Nitride Series-Biased Micro-LED Array

“…On the other hand, the modulation bandwidth of this array is even higher than the one of the single µLED element at the same operating current density. The observed higher modulation bandwidth of the series-biased µLED array is attributed to its lower capacitance due to the series-connection configuration, which is consistent with the one reported in [19]. We are currently working on the performance comparison between the single µLED elements, series-biased µLED array, parallelbiased µLED array and broad LEDs to systemically investigate the advantages of the series-biased µLED array for VLC applications and underlying physical mechanisms.…”

“…On the other hand, compared with the individual LED elements in the array, while retaining the fast modulation speed, the optical power of these arrays is much higher. Recently, this hypothesis has been proved in [19], which demonstrates that, as the number of LED element-in-series increases, the modulation bandwidth and optical power increase at the same operation current density. However, to the best of our knowledge, there is as yet no work demonstrating the data rates of VLC applications based on the series-biased LED arrays.…”

Characteristics of Micro‐Size Light‐Emitting Diode for Illumination and Visible Light Communication

“…The picture of EOC in Figure 3(c) implies that the electrodes could be optimized further to enhance the current spreading and the light extraction, which are advantageous for both illumination and communication. In this section, the diameters of the pelectrodes are in the range of [40,30,20,10] mm and the widths of the n-electrodes are 5 or 10 mm, while the diameters of the mesas are fixed at 120 mm. Figure 6 shows the forward voltage, luminous flux, luminous efficiency, and WLD of the 120 mm-diameter pixels with various size of electrodes in the COB packaged white-LED devices.…”

“…The light‐output power in the order of milliwatt may be adequate for the photoelectric detectors as a signal emitter, but the corresponding luminous flux is not enough for the human eyes as an illumination source. Thus, the arrayed micro‐pixels are adopted to raise the total luminous flux …”

“…Thus, the arrayed micro-pixels are adopted to raise the total luminous flux. [8][9][10] To make sure the white-LED module with arrayed micropixels has adequate luminous flux to meet the lighting requirement and possesses high modulation bandwidth to match the communication function, the suitable structure parameters should be adopted and the appropriate current density should be applied. Although the size-dependent effects on the electrical and optical characteristics have been studied in several published papers, [11][12][13][14][15] there is no comprehensive study of the structure parameters, including the sizes of the mesa and the electrodes, and the current density for electrical, optical, and communication characteristics.…”