Study On Flexible Electroluminescent Device Based On Ag-PI Structure And Its Application

Electroluminescence(EL)is an important luminescent technology,which has been applied in some fields.However,at present,EL devices mostly use the rigid substrates and their functionality is also single or limited,which limits their practical application range.The rapid popularization of wearable electronic devices puts forward higher requirements for the flexibility of EL devices.The research of highly flexible EL devices is accord with the needs of application markets in various fields.Therefore,in terms of structure optimization and application,this thesis makes an innovative development of EL devices,overcomes the shortcomings of inorganic transparent electrode,designs and manufactures a flexible EL device with flexible Ag-polyimide(PI)composite structure as electrode,and explores its potential application in the field of information light source and temperature monitoring.The main research contents of this thesis are as follows:Firstly,highly flexible Ag-PI thin film electrode for EL was prepared by PI surface metallization technology.The influence of process parameters on the conductivity of the electrode was studied,and the corresponding optimized parameters were obtained.The experimental results show that the optimized electrode has compact and uniform structure and good mechanical properties.Secondly,the flexible EL device employing the optimized Ag-PI thin film electrode was fabricated.The corresponding optical,electrical,mechanical properties of the resulted EL device are studied through the home-made testing system.The spectral test data show that the lighting intensities of EL device show the positive correlation with the electrode conductivity,the light-emitting layer thickness and the driving voltage.Through the electrical characterization of Q?V Lissajous figure,the measured power consumption of EL device is about 2.03 m W.There is no obvious change between the device performance even after 4000 bending times or 0°?210° bending angle tests,indicating that the EL device has good flexibility and excellent mechanical robust properties.The test results of 500 cycles of on-off,10 hours of continuous operation and surface temperature of the EL device showed that the EL device has good repeatability and stability.Thirdly,the potential application of as prepared flexible EL devices was studied.On the one hand,the flexible patterned EL devices shaped as QR code as the flexible,light weight and low power omnidirectional light indicator,the landing system for unmanned aerial vehicles(UAVs)were designed.The corresponding wireless control systems were developed.The experimental results show that the application can effectively improve the information recognition effect in weak light environment and significantly improve the night information recognition rate.On the other hand,with the aid of thermochromic(TC)materials,an innovative visual temperature monitoring device based on temperature colorimetry was designed.According to the temperature sensing principle,the invisible temperature change is transformed into the visible light source color change,so as to realize the visual temperature monitoring.