Light-emitting diodes (LEDs) with high response frequency and high power can be applied in visible light communication (VLC). This paper studies the response frequency and optical output power of the gallium nitride (GaN) based matrix micro-LED (μLED) for visible light communication. The blue-emitting GaN μLEDs with the format from 1×1 to 6×6 are fabricated and used to analyze the relationship between the matrix format and the response frequency, as well as the output optical power and the data transmission performance of the matrix μLED. The experimental and analysis results show that the GaN-based matrix μLED response frequency can be improved by an increase in the injection current density increased and a decrease in device capacitance. The experimental comparison result indicates that the −3 dB response frequency changed from 85 MHz to 401 MHz at a 60 mA injection current progressively increased as the matrix array size from 1×1 to 6×6，the 6×6 matrix μLED optical output power reaches a value of 356.7 mW.

A GaN-based vertical superjunction high electron mobility transistor (SJ HEMT) with a composite structure (CS-SJ HEMT) is proposed and analyzed by Silvaco TCAD to improve the breakdown voltage and specific on-resistance (R _onA ). In this paper, CS-SJ HEMT is compared with SJ HEMT with traditional structure (TS-SJ HEMT), SJ HEMT with only particular doping pillars (DP-SJ HEMT) and SJ HEMT with only special P-gate (SP-SJ HEMT). The particular doping pillars mean the doping concentration of n-pillar increases with a gradient from top to bottom, and the concentration of p-pillar is the same as the middle of n-pillar, which reduces the R _onA by only 4%. The special P-GaN cap layer can reduce the R _onA by 10%, and it can even increase the on-state current in the saturation region. The CS-SJ HEMT combines both doping pillars and special P-gate structures, and the R _onA can be reduced by 14%. By the optimized design, the R _onA can be reduced by 30% with BV = 2580 V, or the R _onA can be reduced by 21% with BV = 2720 V. These results show that the composite structure of SJ HEMT contributes to improving the BV and R _onA and propose a useful approach for improving the vertical HEMTs.

In this paper, we introduce a new type of AlGaN/GaN high electron mobility transistor (HEMT) with microfield plate (FP). We use Silvaco-ATLAS two-dimensional numerical simulation to calculate the performance of conventional HEMT and HEMT with micro-FP and analyze its principle. By studying a new charge balance method provided by HEMTs and micro-FPs, the physical mechanism of FP adjusting the HEMT potential distribution and channel electric field distribution is analyzed. The new FP structure consists of a drain field plate (D-FP), a source field plate (S-FP) and several micro-gate field plates (G-FP) to improve the output characteristics of HEMTs. By adjusting the distribution of potential and channel electric field, a wider and more uniform channel electric field can be obtained, and the breakdown voltage can be increased to 1278 V. Although the on-resistance of the HEMT is slightly increased to 5.24 $\Omega$ mm, it is still lower than other reference values. These results may open up a new and effective method for manufacturing high-power devices for power electronics applications.

Deep ultraviolet (DUV) light-emitting diodes (LEDs) have attracted widespread attention in communication because of their lack of background noise interference in day-blind communications, but their low luminous efficiency and low response frequency cannot meet the requirements of non-visual optical communication systems. AlGaN-based micro-LEDs ( $\mu $ -LEDs) can provide high light output power (LOP) due to their smaller chip size, and they can also withstand high current density due to their enhanced current diffusion uniformity. Thus, matrix-type DUV $\mu $ -LEDs are effective candidates to enhance LOP and response frequency. In this work, a matrix-type AlGaN-based DUV communication LED with step-graded Al composition superlattice (SL) electron-blocking layer (EBL) at wavelength of 274 nm was designed, LOP and response frequency reached 45.4 mW and 414 MHz at 212 A/cm2 current density. After this SL EBL applied in the UV communication LED, hole injection capability was enhanced, high LOP and high response frequency make it be an ideal candidate for wireless communication applications.

The advent of mini-light-emitting diodes (mini-LEDs) represents a recent advancement in display technology. The biggest advantage of mini-LEDs over traditional backlight LED panels is that the LED array facilitates the local dimming of light intensity. This paper presents a large-view-angle (LVA) GaN-based mini-LED chip with batwing angular light distribution. By placing a translucent layer on the mini-LED, the angular light-intensity distribution can be modified from the Lambertian type to that resembling a batwing using translucent sublayer pairs. Compared to conventional mini-LEDs, the proposed mini-LED chip requires fewer LEDs and a shorter light-diffusing distance to maintain good uniformity without additional lens packaging. Further, the increased sublayer pair count in the translucent layer affords an increase in the radiation half-power angle from 137.5° to 173.2°. This increases the half-power angle of the mini-LED array from 47.4% to 89.1%. The findings of this study demonstrate significant potential for use in the development of ultrathin backlight panels, which are finding commercial utility in modern television designs. This work should provide the applications solution in mini-LED backlit and wide color gamut RGB backlight display.