Progress in Quantum Electronics 71 (2020) 100263

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Progress in Quantum Electronics

journal homepage: www.elsevier.com/locate/pqe

Growth, transfer printing and colour conversion techniques towards full-colour micro-LED display

Xiaojie Zhou a,1, Pengfei Tian a,*,1, Chin-Wei Sher b, Jiang Wu c, Hezhuang Liu c, Ran Liu a, Hao-Chung Kuo b,** a Institute for Electric Light Sources, School of Information Science and Technology, and Academy of Engineering and Technology, Fudan University, Shanghai, 200433, China b Department of and Institute of Electro-Optical Engineering, National Chiao Tung University, Hsinchu, 30010, Taiwan c Institute of Fundamental and Frontier Sciences, University of Electronic Science and Technology of China, Chengdu, 610054, China

ARTICLE INFO ABSTRACT

Keywords: Micro light-emitting diode (micro-LED) display, mainly based on inorganic GaN-based LED, is an Micro-LED display emerging technique with high contrast, low power consumption, long lifetime and fast response Full-colour time compared to liquid crystal display (LCD) and organic light-emitting diode (OLED) display. Growth Therefore, many research institutes and companies have conducted in-depth research on micro- Transfer printing LED in the full-colour display, gradually realizing the commercialization of micro-LED. And the Colour conversion current research results of micro-LED indicate that it can be widely used in display, visible light communication (VLC), biomedicine and other fields. Although micro-LED has broad commercial prospects, it still faces great challenges, such as the effect of size reduction on performance, the realization of high-density integration on a single wafer for independent addressing of full-colour micro-LED display, the improvement of repair technique and yield et al. This paper reviews the key solutions to the technical difficulties of the full-colour micro-LED display. Specifically, this review analyzes and discusses a variety of advanced full-colour micro-LED display techniques with a focus on three aspects: growth technique, transfer printing technique and colour conversion technique. This review demonstrates the opportunities, progress and challenges of these tech- niques, aiming to guide the development of full-colour micro-LED display.

1. Introduction

In the past decades, display techniques have been rapidly developing, which leads to their wide use. We can find a variety of display applications, including TVs, large video billboards, computers, and especially smart devices, on which people spend much time engaging with the world, making up a typical scene of the modern life [1–4]. The cathode ray tubes (CRTs) accelerated the emergence of video displays, and the history of CRTs has lasted for over half a century [5,6]. In recent years, LCD and OLED display techniques have been widely applied and gradually dominate the display market [7–9]. Various emerging applications of displays, such as virtual reality (VR) and augmented reality (AR), promote the development of high-performance and novel display techniques. Here, micro-LED displays,

* Corresponding author. ** Corresponding author. E-mail addresses: [email protected] (P. Tian), [email protected] (H.-C. Kuo). 1 These authors contributed equally to this work. https://doi.org/10.1016/j.pquantelec.2020.100263

Available online 21 April 2020 0079-6727/© 2020 Elsevier Ltd. All rights reserved. X. Zhou et al. Progress in Quantum Electronics 71 (2020) 100263 mainly based on GaN-based LEDs, are taken as examples. It is noted that various parameters including the dimension of the chip, the number of the and the pixels per inch (PPI) determine the application fields of the micro-LED displays, as shown in Table 1.We mainly show the prototypes from the typical companies, which are the representatives of the progress of up-to-date micro-LED displays. Bes