Study And Finite Element Analysis Of Bending Properties Of Flexible Quantum Dot Light Emitting Devices

Flexible quantum dot light emitting diode(FQLED)not only has the advantages of adjustable emission wavelength,high color purity and strong device stability,but also has the special advantages of flexible,lightweight and simple for preparation.It is a new display technology with wide application prospects.However,there are still some problems in flexible QLED devices,and the microscopic mechanism of the influence of external bending mechanical behavior on the devices is still unclear.Therefore,in this paper,research work has been carried out to explore the causes of the influence of bending on device performance,and the following conclusions have been drawn:In this paper,FQLED devices with the structure of PET / ITO /PEDOT: PSS / TFB / QDs / Zn Mg O / Al were prepared by spin coating and evaporation.The influence of bending behavior on the surface morphology and electrical properties of flexible QLED devices was systematically studied.On the one hand,the mechanical action of different bending radii was applied to it,and the results showed that the smaller the bending radius of curvature,the greater the surface roughness of the device film,the greater the square resistance of the substrate,and the cracks appear on the surface after 50 times of bending.At the same time,due to the weakening of the carrier transport efficiency and the increase of the resistance inside the device caused by the bending,the brightness and current density of the device both decrease with the decrease of the bending radius of curvature.On the other hand,when the bending radius of the device is R=3 mm,the results after different bending times show that the deeper the surface crack of the device film with more bending times,and the square resistance and surface roughness are slightly increased.Excessive bending will weaken the ability of charge transfer,reduce current density,and increase resistance,which will affect the electrical performance of the device.In this paper,the ABAQUS simulation software is used to simulate the process of external bending and internal bending of the mode.The results show that the internal bending is more likely to cause damage to the device than the external bending.On the basis of internal bending,we also analyzed the influence of light-emitting layer materials with different elastic modulus on stress,the results show that the smaller the elastic modulus of light-emitting layer,the greater the degree of bending under the same moment,and the greater the corresponding stress.To sum up,this paper systematically studies the impacts for the degradation of the device performance of flexible QLED devices under the bending behavior,and also verifies the reliability of the experimental results by means of finite element simulation.It has guiding significance for promoting the research on thin film mechanics of flexible QLED devices.