Micro‐LED is an emerging display technology that has great saturated current, low power consumption, great brightness, and high resolution, it is expected to be the next generation of display technology. However, the commercial application of Micro‐LED still faces some difficulties, one of the most important is mass transfer. Mass transfer is a technology used to transfer millions of micro‐LED pixels from the growing sapphire substrate to the glass substrate for display, and it needs to meet the requirements of high efficiency and precision. Many researchers from companies and universities are working on mass transfer technologies and have proposed some methods, one of which is the elastomer stamp micro‐transfer‐printing technology based on adhesion. In this paper, we will review the representative mass transfer technologies and study the basic principles of micro‐transfer‐printing technology and review different implementation methods.

The role of a superlattice distributed Bragg reflector (SL DBR) as the p-type electron blocking layer (EBL) in a GaN micro-light-emitting diode (micro-LED) is numerically investigated to improve wall-plug efficiency (WPE). The DBR consists of AlGaN/GaN superlattice (high refractive index layer) and GaN (low refractive index layer). It is observed that the reflectivity of the p-region and light extraction efficiency (LEE) increase with the number of DBR pairs. The AlGaN/GaN superlattice EBL is well known to reduce the polarization effect and to promote hole injection. Thus, the superlattice DBR structure shows a balanced carrier injection and results in a higher internal quantum efficiency (IQE). In addition, due to the high refractive-index layer replaced by the superlattice, the conductive DBR results in a lower operation voltage. As a result, WPE is improved by 22.9% compared to the identical device with the incorporation of a conventional p-type EBL.

This article reviews a few modulations commonly used in visible light communication with their recent development, explain why applying micro‐LED will benefit the speed, accuracy, secrecy, and how it will expand the application scenarios of visible light communication.

The three‐dimensional display is an important future land for the display industry. To reach a three‐dimensional display, several methods have been improved. For volumetric three‐dimensional display, due to a physical three‐dimensional display volume, the three‐dimensional image can provide an all‐around viewing without wearing any equipment. This article reviews several volumetric display methods using solid‐state volumetric display technology, free‐space volumetric technology, swept volume display technology combined with light field display technology. We discuss the benefits of using various display mediums and structure for a good performance in different situations.

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