Research On The Realization And Perspective Of Tandem White Organic Light Emitting Device

As a new display technology,the Organic Light Emitting Device(OLED)has the advantages of quick response,large viewing Angle,low power consumption and flexibility.Red,green and blue pixels side by side is a common method to realize high resolution display when preparing small and medium size OLED panels.However,this method has many technical difficulties when preparing large-sized OLED panels.To this end,white light OLED combined with color filter is used in large-size OLED panel fabrication.However,there are some problems in white-light OLED devices,such as not getting ideal white light,and color deviation from different perspectives.To this end,this thesis designed a tri-layer structure of tandem WOLED,which connects three light emitting units together through two charge generating layers and each light emitting unit can match the functional layer by energy level matching,and explored its performance as follows:1.By using the optical simulation software Setfos,the performance parameters of WOLED has been obtained.First,the n and k of all functional layer materials in the full band and the photoluminescence spectra of the luminescent material were measured.Secondly,the performance parameters of one complementary color WOLED and six trichromatic colors WOLED under the close CIE coordinate.The position order of the seven WOLED's EML is BYB;BGR;BRG;RGB;RBG;GRB;GBR.Finally,the BYB WOLED structure was determined to have higher device efficiency,light intensity and smaller visual role deviation,and the BYB WOLED structure has been further explored.2.A scheme was designed to optimize the BYB laminated structure WOLED,that is,to optimize the spectral characteristics of the device by changing the position of the luminescent layer in the device.Firstly,a blue OLED was prepared and the position of B-EML was optimized.Furthermore,the bilayer and tri-layer WOLEDs were optimized by adjusting the charge generation layer.Finally,the light color of WOLED was adjusted by micro-cavity effect.Considering the problem of apparent role deviation in practical applications,this thesis optimizes the apparent role deviation by adjusting the micro-cavity length and material refractive index,and finally obtained the WOLED device with an efficiency of 88.48 cd/A,a CIE coordinate of(0.290,0.366)and an apparent role deviation of 0.02.