Study on Angular Dependence in Micro-cavity OLED

The angular dependence of OLED is studied and it showed that the brightness and current efficiency gradually decreased with increased view angle,the intensity and current efficiency at 50 degrees dropped to 1/3 and 40% respectively with respect to the normal direction.And Color coordinates produce drift at a certain extent with increased view angle,but spectral peak and FWHM didn't change depend on the angle.Reasons for the occurrence of angular dependence were discussed.