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.

For high-power applications, it is important to improve the light extraction efficiency and light output of the vertical direction of LEDs. Flip-chip LEDs (FCLEDs) with an Ag/SiO2/distributed Bragg reflector/SiO2 composite reflection micro structure (CRS) were fabricated. Compared with the normal Ag-based FCLEDs, the light output power of the CRS-FCLEDs was increased by 6.3% at an operational current of 1500 mA, with the corresponding external quantum efficiency improved by 6.0%. Further investigation proved that the CRS structure exhibited higher reflectance compared with the commonly used Ag-mirror reflective structure, which originates from the increased reflective area in the sidewall and partial area of the n-GaN contact orifices. It exhibited markedly smaller optical degradation and thus higher device reliability as compared to normal Ag-based FCLED. Moreover, the light emission intensity distributions and far-field angular light emission measurements show that the CRS-FCLED has a strengthened light output in the vertical direction, which shows great potential for applications in high-power fields, such as headlamps for automobiles.

Core–shell heterojunction structure is a feasible approach to optimize the optoelectronic performance of devices by combining the advantages of different materials. In this work, GaN/AlN core–shell heterojunction microwire‐based photodetector (PD) has been fabricated, and appropriate epitaxy growth of AlN can improve the performances of PDs. Compared with pure GaN microwire device, the enhanced responsivity, sensitivity, detectivity, and external quantum efficiency value of 4160 A W−1, 1.88 × 107%, 3.93 × 1012 Jones, and 4.07 × 106% are obtained with 5 nm thick AlN. Meanwhile, a rise/decay time of 25/16 ms is possessed. In addition, the responsivity and detectivity are increased with an acceptable decrease in sensitivity when the exciting light intensity decreases. The effective advances of PDs are benefited from the increased Schottky barrier height, the built‐in electric field that promotes the separation of photogenerated electron‐hole pairs, and direct heteroepitaxial growth high crystal quality GaN/AlN core/shell structure, which will effectively passivate the surface of GaN microwire by covering AlN. This study sheds some light on fabricating high‐performance microwire‐based PDs.