Mini-LED, Micro-LED and OLED displays: present status and future perspectives

Smaller LEDs usher in more advanced displays Mini and micro light-emitting diodes (LEDs) could move to the centre-stage of display screen technologies once they mature. Shin-Tson Wu of the University of Central Florida and colleagues analysed the pros, cons, and future prospects of the latest display screen technologies, especially for use in smartphones, smart watches, virtual and augmented reality, and heads-up vehicle displays. These applications require bright, flexible, transparent, and power-efficient displays. The currently dominant liquid crystal displays (LCDs) require a backlight unit, dictating their shape and flexibility. LCDs with a backlight unit made from mini LEDs are becoming rapid contenders to the conventional technology. So are displays using organic light-emitting diodes, but these are limited in their brightness and lifespans. Emissive displays made from mini and micro-LEDs show huge potential once manufacturing costs can be brought down. Presently, liquid crystal displays (LCDs) and organic light-emitting diode (OLED) displays are two dominant flat panel display technologies. Recently, inorganic mini-LEDs (mLEDs) and micro-LEDs (mu LEDs) have emerged by significantly enhancing the dynamic range of LCDs or as sunlight readable emissive displays. mLED, OLED, or mu LED: who wins? is a heated debatable question. In this review, we conduct a comprehensive analysis on the material properties, device structures, and performance of mLED/mu LED/OLED emissive displays and mLED backlit LCDs. We evaluate the power consumption and ambient contrast ratio of each display in depth and systematically compare the motion picture response time, dynamic range, and adaptability to flexible/transparent displays. The pros and cons of mLED, OLED, and mu LED displays are analysed, and their future perspectives are discussed.