OLED Revolution: Uncovering the scientific miracle behind self-luminous screens
Summary：
OLED technology takes self-luminous characteristics as the core, and realizes pixel-level precise light control through the principle of electroluminescence.Its structural innovation has brought revolutionary advantages of high contrast, millisecond response and flexible form, which is reshaping the future pattern of the display industry.This article will analyze the six core principles and their technical influence in depth.
1. Electroluminescence: the Quantum Dance of Energy Conversion
The luminous essence of OLED is the quantum process by which electrical energy is directly converted into light energy.When an electric current passes through the organic light-emitting layer, electrons and holes are combined under the drive of an electric field, and the released energy excites the organic molecules to transition to the excited state, and photons are released when they fall back to the ground state.This direct light-emitting mode eliminates the backlight layer and color filter required for traditional LCD, and the structure is greatly simplified.
2. Self-luminous structure: the Declaration of Independence of pixels
The “sandwich structure” of OLED (anode-organic layer-cathode) gives each pixel the ability to emit light autonomously.Compared with the global backlight of LCD (such as Samsung QLED, which requires quantum dot layer assistance), OLED pixels can be switched independently.This structural characteristic eliminates the phenomenon of light leakage and lays the physical foundation for the realization of pure blackness.
3. Pixel-level light control: password for unlimited contrast
The self-luminous characteristics give OLED the ability to accurately control light at the pixel level.When displaying a black scene, the pixels can be completely turned off to achieve theoretically unlimited contrast.DisplayMate laboratory tests show that the contrast ratio of the top OLED screen can reach more than 1,000,000:1, far exceeding the 4000:1 level of LCD.
4. Millisecond response: End motion blur
The response speed of organic luminescent materials reaches the microsecond level (about 0.1ms), which is a thousand times faster than the millisecond response (5-10ms) of LCD liquid crystal molecules.In NASA’s high-speed photography research, the OLED screen perfectly captured the flight trajectory of the bullet, completely eliminating the motion blur phenomenon.
5. Flexible genes: Reconstruction of display morphology
OLED does not require a rigid backlight module, and the organic layer can be deposited on a flexible substrate (such as polyimide).In 2013, LG debuted a curved OLED TV in the world, and in 2019, Samsung Galaxy Fold realized screen folding, and the flexible display moved from concept to mass production.
6. Material evolution: the transition from fluorescence to phosphorescence
The first generation of OLEDs uses fluorescent materials (only 25% singlet excitons are used).In 2001, the Forrest team at Princeton University made a breakthrough in the development of phosphorescent materials (which can capture 100% excitons), which increased the efficiency of blue light by 4 times.In 2022, UDC’s new iridium complex phosphorescent material will extend the life of blue light devices to 500,000 hours.
Conclusie
OLED takes electroluminescence as the physical cornerstone, realizes pixel-level light control through a self-luminous structure, and relies on the three characteristics of infinite contrast, instantaneous response, and flexible plasticity to bring a paradigm revolution to the display field.With the maturity of inkjet printing manufacturing technology (such as JOLED mass production technology) and the development of laminated structure (LG 2023 MLA technology to increase brightness to 3000 nits), this technology is breaking through the constraints of cost and life.When the screen is curled like paper and transparent like glass, we will finally understand that the essence of display technology is not to present light, but to control light itself.
Authoritative reference[Nature: Breakthrough in Phosphorescent Materials] (https://www.nature.com/articles/35098048 )[SID: Flexible Display Technology Roadmap] (https://www.sid.org )
DisplayMate Evaluation Methodology[UDC Phosphorescent Materials White Paper] (https://www.oled.com )[IDC Display Market Forecast] (https://www.idc.com )