The LED display uses a metal material, while the OLED display uses an organic material. The light-emitting principle of the two is the same. The difference is that the OLED display does not require a backlight source and emits light by itself. It is composed of an LED array. The brightness is higher than that of the LED display liquid crystal, and the thickness is thinner. It is a replacement for the LED display LCD screen in the future. The LED display LCD screen requires a backlight source, and the brightness is average, and the display is low in daylight. , But currently widely used.
LED display applications can be divided into two categories: one is LED display single-tube applications, including backlight LED displays, infrared LED displays, etc .; the other is LED display displays. At present, China is the basic material of LED display. There is still a certain gap between the manufacturing aspect and the international level, but as far as LED display screens are concerned, China's design and production technology level is basically synchronized with the international level.
The LED display screen is a display device composed of an array of light emitting diodes. It adopts low-voltage scanning drive, which has the characteristics of less power consumption, long service life, low cost, high brightness, less failure, large viewing angle, and long viewing distance.
OLED display is an organic light-emitting display. It belongs to the newly emerging category on mobile phone LCD and is known as "dream display". OLED display screen display technology is different from the traditional LCD display method. No backlight is required. Very thin organic material coating and glass substrate or special plastic substrate are used. When an electric current passes, these organic materials will emit light. . In addition, the OLED display display screen can be made lighter and thinner, with a larger viewing angle, and can significantly save power. However, although OLED display screens with better technology will replace LCDs such as TFT in the future, organic light-emitting display technologies still have shortcomings such as short service life and difficult screen size.
OLED display: also known as organic EL display, is an organic light emitting diode. The basic structure of the OLED display screen is a thin and transparent indium tin oxide (ITO) with semiconductor characteristics, which is connected to the positive electrode of electricity, plus another metal cathode, wrapped into a sandwich-like structure. The entire structure layer includes a hole transport layer (HTL), a light emitting layer (EL), and an electron transport layer (ETL). When the power is supplied to an appropriate voltage, the positive electrode holes and the cathode charges are combined in the light-emitting layer to produce light, and the three primary colors of red, green, and blue RGB are formed according to different formulas, which constitute a basic color. OLED display The characteristic of the display is that it emits light by itself, unlike TFT? LCD requires backlight, so both visibility and brightness are high, followed by low voltage demand and high power saving efficiency, coupled with fast response, light weight, thin thickness, simple structure, low cost, etc., are considered as? One of the more promising products of the 21st century.
The light-emitting principle of organic light-emitting diodes is similar to that of inorganic light-emitting diodes. When the element is forward biased by direct current, the applied voltage energy will drive electrons and holes into the element from the cathode and anode respectively. When the two meet and combine in conduction, they form a so-called electron-hole recombination. When a chemical molecule is excited by external energy, if the electron spin and the ground state electron are paired, it is a singlet state, and the light emitted is so-called fluorescence; on the other hand, if the excited state electron and the ground state electron are unpaired and Parallel is called triplet, and the light it releases is called phosphorescence.
When the state of the electron is returned from the excited high energy level to the stable low energy level, its energy will be released as a photon or thermal energy, respectively, where the photon portion can be used as a display function; however, organic fluorescent materials at room temperature and Triplet phosphorescence cannot be observed, so the theoretical limit of the luminous efficiency of PM-OLED display screen elements is only 25%.
