کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1788119 | 1023459 | 2012 | 5 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Effect of different spacers for performance enhancement on white organic light-emitting devices based on double emissive layers with homogeneous p-/n-type host Effect of different spacers for performance enhancement on white organic light-emitting devices based on double emissive layers with homogeneous p-/n-type host](/preview/png/1788119.png)
White organic light-emitting devices (WOLEDs) based on phosphorescent blue and yellow emitters were fabricated, while p-type di-(4-(N,N-ditolyl-amino)-phenyl)cyclohexane (TAPC) and n-type 2,2′,2″-(1,3,5-benzenetriyl)-tris(1-phenyl-1-H-benzimidazole) (TPBi) were separately utilized as a homogeneous host for both blue and yellow emissive layers (EMLs). Then, various spacers were inserted between the two EMLs for performance characterization. The results showed that for the TAPC-host devices, a device using 4,7-diphenyl-1,10-phenanthroline (Bphen) as the spacer had a maximum current efficiency (CE) of 11.3 cd/A, while stable white light emission with Commission Internationale del’Eclairage (CIE) coordinates of (0.394, 0.435) at a bias of 5 V was observed. Similarly, among the TPBi-host devices, a device using 4,4′-bis(carbazol-9-yl)biphenyl (CBP) as the spacer exhibited a maximum CE of 18.1 cd/A, accompanied by negligible color variation with the CIE coordinates of (0.284,0.333) at 5 V. For the double-EML devices, the improved device efficiency and color stability by introducing proper spacer was attributed to broadened recombination region and efficient energy transfer between the EMLs.
► We demonstrated phosphorescent white organic light-emitting devices consisting of blue and yellow EMLs.
► The p-type TAPC and n-type TPBi were separately used as homogeneous host of the EMLs.
► Various spacers were separately inserted between the two EMLs for performance enhancement.
► High efficiency and stable white emission were achieved through the employment of suitable spacer.
Journal: Current Applied Physics - Volume 12, Issue 4, July 2012, Pages 1212–1216