Influence Of Functional Layer On The Lifetime Of OLED Device

Organic light-emitting diodes(OLED)have attracted researchers' attention due to its many advantages,and may gradually replace liquid crystal display as the next generation mainstream display technology in the future.OLED has a history of more than 70 years since its discovery.Over the years,the research and development of OLED devices have continuously improved and optimized the performance of devices.However,OLED still has some disadvantages,such as not having a long service lifetime,not being able to achieve very high resolution,and being expensive.In this paper,we will briefly introduce the basic knowledge of OLED devices,improve the commercial OLED devices and materials,and improve the lifetime of the devices.The main contents are as follows:1.The life problems faced by OLED at present are studied.Through investigation and analysis,it is confirmed that starting from the essential aging in the aging mechanism of OLED devices,the core problem is to balance the carriers in the device.2.The single-carrier device is prepared,and the exciton recombination region in the luminescent layer in the existing structure system is studied and analyzed,and then the corresponding experiment plan is made to improve the device life.The results show that the composite region is close to the electron transport layer.3.To solve the problem of rapid aging of blue and red OLEDs,the existing device structure was improved.By adding a hole barrier layer,the device life was improved.The influence of different electron injection on the performance and lifetime of the device was studied.Finally,different electron transport materials are used to explore the influence of their performance on the device.4.The selection of the main material is further clarified,and the influence on the device performance is studied by replacing the main material;Then adjust the thickness of hole injection and hole transport film to choose a more suitable device structure.The hole transport material is replaced,and the carrier mobility is better matched with the hole transport material to transfer the carrier,so that the carrier in the device is kept in balance.In the face of phosphorescent material,the electronic barrier layer was replaced,and its effect on the device performance was analyzed.Finally,the lifetime of the improved device has been greatly improved compared with that of the unimproved device.The lifetime of blue OLED devices at LT90 increased from 3.73 hours to 53.13 hours,an increase of 14.2 times.The lifetime of red OLED devices at LT97 increased from 13.65 hours to 63.47 hours,an increase of 4.43 times.Starting from the aging mechanism,this paper improves the lifetime of OLED devices by improving the functional layer structure and materials.Its core lies in the balance of carrier,which has certain significance for the improvement of device lifetime.