LAMPLIC CO.,LTD is committed to providing a comprehensive UV LED curing solution, which has been widely used in various fields, including LCD touch screen curing, UV lens curing, electronic components curing and so on. Organic Light-Emitting Diode (OLED) is also known as organic laser display and organic light-emitting semiconductor. Ching W. Tang, a Chinese-American professor, discovered it in his laboratory in 1979. OLED display technology has the advantages of self-luminescence, wide viewing angle, almost infinitely high contrast, low power consumption and extremely high reaction speed. However, as a high-end display screen, the price will be more expensive than LCD TV.
OLED display technology has the characteristics of self-luminescence. It uses very thin organic material coating and glass substrate. When current passes through, these organic materials will emit light. Moreover, OLED display screen has a large visual angle and can save electricity. Since 2003, this display device has been applied in MP3 player.
 In terms of organic light-emitting materials used in OLED, one is small molecular device system using dyes and pigments as materials, the other is polymer device system using conjugated polymers as materials. At the same time, because organic light-emitting devices have the characteristics of light-emitting diode rectification and light-emitting, small molecular organic light-emitting devices are also called OLED (Organic Light Emitting Diode), and polymer organic light-emitting devices are called PLED (Polymer Light-emitting Diode). Small molecule OLEDs and high molecule OLEDs have their own merits in material properties. However, with the development of existing technology, small molecule OLEDs are in the leading position in terms of reliability as monitors, electrical characteristics and production stability. At present, the OLED components put into mass production are all made of small molecular organic light-emitting materials. The basic structure of OLED is a sandwich-like structure consisting of a thin transparent ITO connected to the positive pole of electric power and another metal cathode. The whole structure layer includes: Hole Transport Layer (HTL), Light Emission Layer (EL) and Electron Transport Layer (ETL). When the power is supplied to the appropriate voltage, the positive hole and the cathode charge will combine in the luminescent layer to produce brightness. According to the formula, the red, green and blue RGB three primary colors will be produced, forming the basic color. OLED is characterized by its own luminescence, unlike TFT LCD, which requires backlight, so its visibility and brightness are high, followed by low voltage demand and high power-saving efficiency. With fast response, light weight, thin thickness, simple structure and low cost, OLED is regarded as one of the most promising products in the 21st century.
The light-emitting principle of organic light-emitting diodes is similar to that of inorganic light-emitting diodes. When the component is subjected to the forward bias voltage derived from direct current (DC), the additional voltage energy injects the driving electrons (Electron) and holes (Hole) into the component from the cathode and the anode respectively. When the two meet and combine in conduction, they form the so-called electron-Hole Capture. When a chemical molecule is excited by an external energy, if the electron spin pairs with the ground state electrons, it is a singlet, and the light released by it is called fluorescence; otherwise, if the excited state electrons and the ground state electrons are not paired and parallel, it is called a triple state (Triplet). The light it emits is called phosphorescence.
When the state position of electrons returns to the steady-state low-energy level from the excitation high-energy level, their energy will be emitted in the form of photon (Light Emission) or thermal energy (Heat Dissipation), where the photon part can be used as a display function; however, the triplet phosphorescence can not be observed in organic fluorescent materials at room temperature, so PM-OL The theoretical limit of the luminous efficiency of ED devices is only 25%.
The principle of PM-OLED is to convert the released energy into photons by using the energy gradient of materials, so we can choose suitable materials as the luminescent layer or doping dyes in the luminescent layer to get the luminescent color we need. In addition, the binding reaction between electrons and holes is usually within tens of nanoseconds, so PM-OLED responds very quickly. In addition to glass substrates, cathode and anode electrodes and organic light-emitting layers, multi-layer PM-OLED structures with better luminescence efficiency need to be fabricated as Hole Inject Layer (HIL), Hole Transport Layer (HTL), Electron Transport Layer (ETL) and Electron Injection Layer (EIL). Electron Inject Layer (EIL) and other structures, and the transmission layer and the electrode need to be insulated layer, so hot evaporation (Evaporate) processing is relatively difficult, and the manufacturing process is also complicated. Because organic materials and metals are sensitive to oxygen and water, they need to be encapsulated and protected after fabrication. Although PM-OLED is composed of several layers of organic thin films, the thickness of organic thin films is only 1000-1500A degree (0.10-0.15 um). The total thickness of the whole panel is less than 200 um (0.2 mm) after packaging and desiccant.