MicroLED

MicroLED, also known as micro-LED, mLED or μLED is an emerging flat-panel display technology consisting of arrays of microscopic LEDs forming the individual pixel elements.

The first high-resolution and video-capable InGaN microLED microdisplay in VGA format was realized in 2009 by Jiang, Lin and their colleagues at Texas Tech University and III-N Technology, Inc. via active driving of a microLED array by a complementary metal-oxide semiconductor (CMOS) IC.

[6] Compared to widespread LCD technology, microLED displays offer better contrast, response times, and energy efficiency.

[7][8] The inorganic nature of microLEDs gives them a longer lifetime advantage over OLEDs and allows them to display brighter images with minimal risk of screen burn-in.

[7] MicroLEDs are capable of high speed modulation, and have been proposed for chip-to-chip interconnect applications.

Various on-chip connection schemes of microLED pixel arrays have been employed by AC LED Lighting, LLC (a company funded by Jiang and Lin) allowing for the development of single-chip high voltage DC/AC-LEDs[32][33][34][35][36][37][38] to address the compatibility issue between the high voltage electrical infrastructure and low voltage operation nature of LEDs and high brightness self-emissive microdisplays.

[42] Early InGaN based microLED arrays and microdisplays were primarily passively driven.

The first actively driven video-capable self-emissive InGaN microLED microdisplay in VGA format (640 × 480 pixels, each 12 μm in size with 15 μm between them) possessing low voltage requirements was patented and realized in 2009 by Jiang, Lin and their colleagues at Texas Tech and III-N Technology, Inc.(a company funded by Jiang and Lin) via integration between microLED array and CMOS integrated circuit (IC)[6] and the work was also published in the following years.

Faulty LED replacement must be performed using high accuracy pick-and-place machines and the test and repair process takes several hours.

[72][12][73][13][74][75] MicroLEDs have already demonstrated performance advantages over LCD and OLED displays, including higher brightness, lower latency, higher contrast ratio, greater color saturation, intrinsic self-illumination, better efficiency and longer lifetime.

[80] On 12 September 2019, Sony announced Crystal LED availability to consumers ranging from 1080p 110-inch (2.8 m) to 16K 790-inch (20 m) displays.

[84] On June 12 at InfoComm 2019, Samsung announced the global launch of The Wall Luxury microLED display configurable from 73-inch (1.9 m) in 2K to 292-inch (7.4 m) in 8K.

[14][86] In March 2018, Bloomberg reported Apple to have about 300 engineers devoted to in-house development of microLED screens.

[94] At IFA 2019 on September 13, 2019, TCL Corporation demonstrated their Cinema Wall featuring a 4K 132-inch (3.4 m) microLED display with maximum brightness of 1,500 cd/m2 and 2,500,000∶1 contrast ratio produced by their subsidiary China Star Optoelectronics Technology (CSoT).

[99] Apple reportedly invested billions of dollars in development of microLED displays in the years leading up to 2024, intending to transition its products to the technology beginning with the Apple Watch Ultra, before ultimately abandoning the effort after deciding it was unviable.