Micro LED: Revolutionizing Display Technology

Full Name: Micro Light Emitting Diode

Definition: Micro LED is an emerging display technology that utilizes microscopic light-emitting diodes as individual pixel units. Each pixel can be independently controlled by a driving circuit to emit light, enabling high-performance image rendering with superior brightness, contrast, and energy efficiency compared to traditional display technologies.

Technical Principles

A Micro LED display is composed of discrete Micro LED pixel units, each of which has a basic structure similar to conventional LED lighting chips. Its epitaxial structure consists of three core layers: an n-type semiconductor layer, an active region quantum well, and a p-type semiconductor layer.

To achieve full-color display, each pixel unit must integrate three sub-pixels of red, green, and blue (RGB). There are two mainstream technical routes for full-colorization:

Direct RGB Integration: Employing separate red, green, and blue Micro LED chips to form a single full-color pixel unit.
Color Conversion Technology: Using a single-color Micro LED chip (typically blue) as the excitation light source, and converting part of the blue light into red and green light through a color conversion material (e.g., quantum dots) to achieve full-color output.

Key Technical Features

Superior Display QualityUnconstrained by light blockers or color filters, Micro LED displays can achieve a peak brightness ranging from 2000–4000 cd/m². This enables ultra-high contrast ratios and high-quality HDR (High Dynamic Range) display effects, with perfect black levels (by turning off individual pixels) and vivid color reproduction.
High Energy EfficiencyAs a self-illuminating display technology, Micro LED eliminates the light transmission loss inherent in backlit displays like LCD. Its power consumption is 90% lower than that of LCD displays and 50% lower than that of OLED displays, making it ideal for battery-powered devices.
Long Service LifeMicro LED uses inorganic semiconductor materials as the light-emitting medium, which offers excellent stability and resistance to aging. Unlike OLED, it does not suffer from screen burn-in issues, ensuring a significantly longer operational lifespan for the display.

Development History

1999: Cree Inc. of the United States filed a patent titled “Micro LED for Enhanced Light Extraction”, which is recognized as the foundational document for Micro LED display technology.
2012: Sony unveiled a 55-inch Micro LED TV named “Crystal LED Display” at the Consumer Electronics Show (CES), marking the first public demonstration of large-size Micro LED display products.
2018: Samsung launched a 146-inch Micro LED display called “The Wall”, showcasing the scalability of Micro LED technology for large-screen applications.
2020: Leyard Optoelectronics and Epistar Corporation jointly established the world’s first mass production base for Micro LED display products using mass transfer technology. This milestone signaled the official arrival of the commercialization era for Micro LED technology.

Application Fields

Micro LED technology has broad application prospects across multiple industries, including:

Flat-panel displays (high-end TVs, monitors)
AR/VR/MR (Augmented/Virtual/Mixed Reality) devices
Spatial displays (large-scale commercial advertising screens, stadium displays)
Flexible and transparent displays
Wearable devices (smart watches, AR glasses)
In-vehicle displays (dashboard, central control screens)
Optical communication, optical interconnection, and medical detection equipment

Technical Challenges

Despite its advantages, Micro LED technology is still in the early stages of commercialization and faces several key technical bottlenecks:

Bonding Technology: Achieving reliable bonding between Micro LED chips and the backplane while ensuring long-term stability requires further technological breakthroughs.

Wafer Wavelength Uniformity: Current Micro LED wafers cannot meet the wavelength consistency requirements for mass production, leading to color deviation in displays.

Mass Transfer Technology: The process of transferring millions of microscopic LED chips to the display backplane with high precision and yield remains a major challenge.

Full-colorization Optimization: Both direct RGB integration and color conversion routes have room for improvement in terms of cost reduction and color accuracy enhancement.

Driving and Repair Technologies: Developing low-power, high-density driving circuits and efficient pixel repair solutions for Micro LED displays is essential for large-scale production.