Positional Analysis and Comparison of Different Charge Generation Layer Based Blue OLEDs

This paper includes three blue OLED devices which are D1, D2 and D3 where D1 is a non-CGL (charge generation layer) device, and D2 and D3 are CGL based devices. In all the devices, the CGL contains two materials 1.,4.,5.,8.,9.,11-hexaazatriphenylene-hexacarbonitrile (HAT -CN) and 1.,1-bis[(di-4-tolyamino)phenyl)]cyclohexane (TAP C) which act as electron and hole generators, respectively. As CGL provides additional charge carriers to D2 and D3 devices, these devices exhibit noteworthy improvement on the basis of luminescence and current. Among all the three devices, D3 shows the best performance. The luminescence of D3 is 2112.2 cd/m2 which is 10 times and 1.3 times enhanced in comparison with D1 and D2, correspondingly. Additionally, the current of D3 is 0.256 A which is 10 times and 1.4 times higher on comparing with D1 and D2, respectively. Moreover, the internal analysis of the devices is also performed using cutline and structure-based analysis to understand the in-depth performance improvements of D1, D2 and D3. The reported CGL based devices are useful for bio-medical and sensor applications.