What is oled technology? Introduction to oled technical structure and light-emitting principle
Jul 13, 2021
Introduction to oled technology
The full name of oled is OrganicLight-Emitting Diode, also known as organic light-emitting diode. It is a light-emitting component formed by a multilayer organic thin film mechanism. The technology for its production is also very easy, only requiring a lower driving voltage. Simply put, OLED technology refers to the phenomenon that organic semiconductor materials and luminescent materials are driven by an electric field to cause light emission through carrier injection and recombination.
oled technical structure
The structure of oled technology mainly consists of base layer, anode, organic layer, conductive layer, etc., as shown in the figure below. The specific content will be analyzed in detail next.
l Base layer: We can become transparent plastic or glass again, and the base layer can be used to support the entire OLED. It's like the foundation we built before building the house.
l Anode: This structure is to effectively eliminate electrons when the anode current passes through the OLED.
l Organic layer: The structure is mainly composed of organic molecules or organic polymers.
l Conductive layer: The conductive layer is mainly composed of organic plastic molecules, and most of these molecules are produced using anodes during transmission.
l Emission layer: We can also say that the emission layer is made of organic plastic molecules, but unlike the conductive layer, these organic plastic molecules are generated from the cathode during transmission.
l Cathode: Contrary to the anode, the cathode injects electrons into the circuit when there is current passing through the device.
OLED technology light-emitting principle
Compared with common light emitting diodes, the luminescence principle of oled technology is different. The luminescence principle of oled technology can be divided into three types: injection of electrons and holes, transport of electrons and holes, and recombination of electrons and holes. Let's explain in detail next.
1. Injection of electrons and holes: The electrons in the cathode and the holes in the anode will move to the light-emitting layer of the device under the drive of an external driving voltage. In the process of moving to the light-emitting layer of the device, if the device contains electrons In the injection layer and hole injection layer, the electrons and holes first need to overcome the energy barrier between the cathode and the electron injection layer and the anode and the hole injection layer, and then the electrons to the device through the electron injection layer and the hole injection layer The transport layer and the hole transport layer move.
2. Transport of electrons and holes: Driven by an external driving voltage, electrons from the cathode and holes from the anode will move to the electron transport layer and hole transport layer of the device, respectively, and the electron transport layer and hole transport layer will move to the electron transport layer and hole transport layer of the device, respectively. The electrons and holes are respectively moved to the interface of the light-emitting layer of the device, while the electrons of the anode and the cathode are respectively blocked at the interface of the light-emitting layer of the device to promote the continuous accumulation of the interface of the light-emitting layer, thereby emitting light.
3. The recombination of electrons and holes: This luminescence principle is simpler than the former two. When the number of electrons and holes at the interface of the light-emitting layer of the device reaches a certain number, the electrons and holes will recombine and generate excitons in the light-emitting layer.
