A text to understand the difference between OLED and LED light-emitting principle

Today, the LED market has been saturated, the price war intensified, profit margins continue to be compressed. In this context, OLED should be from time to time, to provide a broad prospect for the majority of businesses to open up a new market, then the difference between OLED and LED where, and what is their luminescence principle, we work together to explore

LED is used in metal materials, and OLED is the use of organic materials, the luminescence principle is the same, the difference is that OLED does not require a backlight, their light is composed of light emitting diode array. Brightness than the LED LCD, thinner, need backlight, LED LCD screen substitute.LED LCD screen brightness in the future, in the sunlight shows low degree. However, currently the most widely used.

The LED application can be divided into two categories: one is the single application of LED, including LED backlight, infrared LED; the other is LED display, at present, China manufacturing and international LED based materials there still exists a certain gap, but the LED display, the level of production technology and design China basic synchronization with the international.

The LED display screen is a display device which is composed of a light-emitting diode array. The utility model is characterized in that the utility model has the advantages of low power consumption, long service life, low cost, high brightness, less failure, large viewing angle and far visual distance.

OLED:Organic Light Display Emitting, which is an organic light-emitting display, in the mobile phone LCD is a newly emerging species, known as the "dream display". OLED display technology with traditional LCD different display modes, without backlight, using organic coating and glass substrate or special use plastic substrate material is very thin, when a current is passed, these organic materials will shine. And the OLED display screen can be made lighter, thinner, more visual, and can significantly save power. However, although the future of OLED technology will be better to replace the TFT, such as LCD, but the organic light-emitting display technology also has a short life, large screen defects such as difficult.

OLED: also known as organic EL display, is an organic light-emitting diode (Organic Light-Emitting Diode).

The basic structure of OLED consists of a thin and transparent indium tin oxide (ITO) with a semiconductor characteristic, which is connected to the positive electrode of the power, coupled with another metal cathode, such as a sandwich structure. The whole structure includes the hole transport layer (HTL), the EL and the electron transport layer (ETL). When the power supply to the appropriate voltage, the cathode hole and cathode charge will be combined in the light-emitting layer, resulting in light, according to its formula to produce red, green and blue RGB primary colors, constitute the basic color. The characteristic of OLED is self luminous, unlike TFTLCD therefore require backlighting, visibility and brightness are high, followed by low voltage demand and high efficiency and energy saving, quick reaction, light weight, thin thickness, simple structure, low cost, is regarded as one of the most promising products in twenty-first Century.

The principle of organic light emitting diode is similar to that of inorganic light emitting diode. When the components are subjected to DC (Direct Current; DC) to bias voltage energy derived from CIS, plus the drive electronics (Electron) and hole (Hole) were injected into the components from the cathode and the anode, when the two meet, with the conduction, which form a cavity composite air - the so-called electronic (Electron-Hole Capture). When the chemical molecules by external energy excitation, electron spin (ElectronSpin) and electron pairs for singlet (Singlet), the release of light is called fluorescence (Fluorescence); on the contrary, if the electronic excited state and ground state of the unpaired electron spin and parallel, it is called the three state (Triplet), the release of light is called phosphorescence (Phosphorescence).

When the position of electronic excited state by high level back to the steady state energy band, the energy will be in the photon (Light Emission) or heat (Heat Dissipation) way out, which can be used as a part of the photon display function; natural organic fluorescent materials at room temperature and cannot be observed three triplet phosphorescence, so the PM-OLED element theory of luminescence efficiency limit value of only 25%.

PM-OLED light-emitting principle is the use of material energy gradient, energy will release into photons, so we can choose the appropriate material as a light-emitting layer or in the luminescent dye doped layer to get the colors we need. In addition, the general response of electrons and holes are in the tens of nanoseconds (NS), so the PM-OLED response speed is very fast.

Typical structure of P.S.:PM-OLED. Typical PM-OLED consists of a glass substrate, ITO (indiumtinoxide; indium tin oxide (Anode) anode), organic light emitting layer (Emitting Material Layer) and the cathode (Cathode) etc., among them, thin and transparent ITO anode and metal cathode like sandwiches will be like the organic light emitting layer sandwiched between them, when the anode voltage injection the hole (Hole) and the cathode (Electron) in the organic light emitting layer combination, excite organic luminescent materials.

At present, the luminous efficiency is good, widely used multilayer PM-OLED structure, in addition to the glass substrate, the electrode and the organic light emitting layer, still need to make a hole injection layer (Hole Inject Layer; HIL), a hole transport layer (Hole Transport Layer; HTL) and electron transport layer (Electron Transport Layer; ETL) and electronic injection layer (Electron Inject Layer; EIL) structure, and between the transmission layer and the electrode set insulation layer, the thermal evaporation (Evaporate) process is relatively difficult to mention