Journal article
Undoped White Organic Light-Emitting Diodes Utilizing Two Sources of Excitons
Yoga Divayana Sun Xiaowei Chen Baijun Guo Qiang Lo Changyun Jiang Dim Lee Kwong Kalluri R Sarma
Volume : 46 Nomor : 8 Published : 2017, August
Japanese Journal of Appied Physics
Abstrak
We report two undoped white organic light-emitting diodes with the structures of ITO/m-MTDATA/Alq3/NPB/BCP/Alq3/ Mg:Ag (device A), and ITO/NPB/DCM/NPB/Alq3/NPB/BCP/Alq3/Mg:Ag (device B), where ITO is indium tin oxide, m-MTDATA is 4,40,400-tris{N,(3-methylphenyl)-N-phenylamino}-triphenylamine, Alq3 is tris(8-hydroxyquinoline) aluminum, NPB is N,N0-di(naphth-2-yl)-N,N0-diphenyl-benzidine, BCP is 2,9-dimethyl-4,7-diphenylphenanthroline, and DCM is 4-(dicyanomethylene)-2-methyl-6-(p-dimethyl aminostyryl)-4H-pyran. Red emission was harvested from the exciplex at the m-MTDATA/Alq3 interface and DCM (0.5nm) for devices A and B, respectively, while green and blue emissions were from Alq3 and NPB respectively, for both devices. A maximum brightness of 1100 and 4500cd/m2 was achieved at a current density of 270mA/cm2 (12V) for devices A and B, respectively. Device B showed a maximum external quantum e?ciency of 0.89% photon/electron (2cd/A), which is about four times of that of device A.