What are the characteristics of single layer and double layer OLED?

According to its different structures, OLED can be divided into single-layer devices, double-layer devices, three-layer devices and multi-layer devices, and each classification has its own unique characteristics. Single-layer devices and double-layer devices have certain commonalities in their structures, and it can be said that double-layer devices are an upgrade on the basis of single-layer devices.

Single-layer structureSingle-layer structure is the simplest structure in OLED, which is very simple, but it is precisely because of this simplicity that it often leads to unbalanced carrier injection, which causes a series of problems and significantly reduces the efficiency of the device. The single-layer device composed of a single-layer structure is relatively poor in terms of brightness and stability.

The double-layer structure is precisely because of some shortcomings of the single-layer device composed of the single-layer structure, and on this basis, a certain upgrade has been made, and finally the double-layer device is formed. This structure effectively overcomes the problem of carrier injection imbalance in the single-layer structure. The luminous intensity of the device that is made up of this structure.

It is linearly related to the current density, and its appearance effectively improves the voltage-current characteristics of the device and effectively improves the luminous efficiency of the device.

In fact, whether it is a single-layer structure or a double-layer structure, it is a functional upgrade of OLED, from a simple single-layer device to a slightly complex double-layer device, and later a three-layer device and multi-layer device, which is also an upgrade of the OLED industry chain. At present, single-layer devices and double-layer devices are not used frequently, and with the demand of the market, the three-layer device structure is the most widely used structure. This is because this structure improves the efficiency of the device compared to the previous two structures.

For OLED, from a single-layer structure to a double-layer structure, then to a three-layer structure, and finally to a multi-layer structure, this is an upgrade from low efficiency, poor stability to high efficiency and strong stability, whether it is a single-layer structure or a double-layer structure, it is no longer suitable for the OLED market.

The carrier injection of single-layer devices is unbalanced, and the device efficiency is low. The efficiency of the double layer increases first and then decreases with the increase of brightness.

Double-layer OLED will cause refraction due to the middle layer of medium, and the image will be distorted, while the single-layer OLED phenomenon is better.

The carrier injection of single-layer OLED is unbalanced, which is easy to cause the luminescence quenching of metal electrode pairs. On the other hand, bilayer OLED has a high hole mobility and can use the hole transport material as a light-emitting layer.