Effect of a P-doped hole transport and charge generation layer on single and two-tandem blue top-emitting organic light-emitting diodes

摘要

Thetransmittanceofthep-dopedholetransportinglayer(p-HTL)andthechargegenerationlayer(p- CGL)correspondingtothephotoluminescence(PL)ofbluedopantsinanemittinglayerdecreasesas the ratio of the p-dopant increases due to the absorption of the p-dopant. However, there was little differenceintheluminousefficiencyofbluetop-emittingorganiclight-emittingdiodesusingp-HTL or p-CGL at a maximum doping ratio of 20%. p-HTL for a single structure required a 5% doping ratio to ensure sufficient electrical characteristics, but p-CGL for the two-stack tandem structure required more than a 10% doping ratio. The optical simulation showed that the device was affected by the specific absorbance of the p-dopant depending on the doping ratio and thickness. Although there wasnosignificantdifferenceinefficiencydependingonthedopingratioatathicknessof10nm,the reductionrateoftheexternalquantumefficiencyincreasedfromover20nmduetothedopingratio.