The invention of LED has saved energy and changed the way information is transmitted
LED stands for Organic Light Emitting Diode. The technology is different from OLED displays and is mainly used for general lighting and automotive applications. Having advantages such as uniform luminescence, ultra-thin and lightweight appearance, it is more suitable for these application fields.
The technology can be used to construct solid-state lighting (SSL), which consists of a thin carbon based organic layer sandwiched between two electrodes. When direct current is applied, holes and electrons are injected into the organic layer from the anode and cathode respectively, forming excited states on the organic molecules. When the excited exciton transitions to the ground state, electroluminescence occurs, resulting in the emission of light.
The color or wavelength of the light emitted depends on the structure of the organic molecules that form the excited state. Technically speaking, there are multiple colors of light to choose from. Lighting, on the other hand, is a mixture of carefully screened organic compounds to achieve the desired white light spectrum.
The lighting panel adopts a transparent substrate that provides mechanical structure and required optical properties. The substrate includes a patterned transparent conductive layer, typically indium tin oxide used as the bottom electrode or anode. An ultra-thin layer of organic material is placed on the surface of the anode, followed by a metal cathode or second electrode. The entire OLED stack structure is thinner than a single hair, and each layer can contain multiple organic materials.
Unlike inorganic LEDs, organic materials are disordered and do not require the formation of single crystals to efficiently emit light, nor do they need to be placed on expensive crystal substrates. Therefore, the illuminated luminous area can cover most of the substrate and provide a wide-angle, low glare, and hotspot free light source, which is very suitable for large-area light sources. When electrodes are patterned, the broad and flat light emission also has the ability to selectively target specific areas of panels with high contrast, conveying additional communication information through movement, customization, and branding.