Development And Research On The Top Emission OLED Device

Development and research of AMOLED display includes electronic,optical simulation,organic material,LTPS back plant process,OLED evaporation process and module process technology etc.In this paper,we will focus on top emission device simulation and manufacture.Study the optical character that includes spectrum,color coordinate and viewing angle,try to find what the relationship between different cavity length,CPL thickness and optical character.It includes four portions as below: 1.Introduce the current status of the AMOLED marketing and AMOLED basic theory.Meanwhile,introduced the background and the target of this project.2.Introduce the principle tools of top emission device optical design,it includes optical transmission character,thin film system calculation and trichromatic theory,and derive the formula of transmittance and reflection of thin film system.3.Introduce top emission device micro-cavity theory and derive the formula of luminous intensity.Meanwhile,introduced Simoled optical simulation software,select suitable material of electrode and organic layer.And then do the simulation of this device,study different thickness of CPL Alq3 Vs transmittance.Compare two device optical character which with CPL and without CPL,it includes color coordinate,spectrum and viewing angle dependence.Study different NPB thickness Vs device's optical character,and find the optimal top emission device as below structure: Anode(Ag/Mo O3,100nm/3nm),HTL(NPB,70nm),EML(Alq3,60nm),Cathode(Li F/Al,1nm/1nm,Ag,25nm),CPL(Alq3,50nm)? 4.Base on software simulation result,we produce device A~E,and introduce the device manufacture process and critical process parameter,compare the truly device optical character with simulated device.The difference of device A and device is without CPL and with 50 nm Alq3 CPL,Device C and D have different NPB thickness(30nm,110nm),Deivce E is bottom emission as reference.The wavelength peak of Device A and B is 512 nm and 530 nm respective,color coordinate is(0.2,0,73),(0.18,0.7),viewing angle change from 0 degree to 60 degree,the peak of wavelength shift to shorten wavelength,and shift 24 nm and 8nm respective,CIE_x,CIE_y shift(0.06,0.1),(0.01,0.05).Compare with device B,C,D,accompanied with cavity length increasing,the peak of wavelength shift to red wavelength.Viewing angle change from 0 degree to 60 degree,the peak of wavelength shift to blue wavelength.Compare bottom emission device E with top emission device B,it can narrowing the spectrum and improve the color purity.Meanwhile,the device B can meet of design target requirement,and almost same with of simulate result by Simoled optical software.Finally,summary the development of green top emission device,analysis the problem and provide action plan,give outlook of the next work,which include red,blue monochrome device and white device development.