Improving Performance of Quantum Dot Light-emitting Diode with Self-immersed Nanoimprint-coupling
Colloidal quantum dot materials have been widely studied for their excellent narrow emission spectra,tunable emission wavelengths,high luminous efficiencies and excellent stability,and their simultaneous solution-pro-cessability has made quantum dot light-emitting diodes(QLEDs)widely applicable and used.However,the inherent substrate mode within the device leads to a large amount of photons in QLED devices being confined internally and not utilized.In this work,a solvent self-infiltration nanoimprinting process is developed based on the traditional na-noimprinting process while utilizing the surface binding energy of polydimethylsiloxane(PDMS)material itself,which has low pressure dependence and simplifies the traditional process flow,and based on which the micro-nano-structured patterns in three sizes of 1.3,1,0.5 μm with high periodicity are produced.Micro-nano-structured pat-terned layers of three sizes were fabricated based on which the red,green and blue QLED devices were out-coupled to realize light extraction.In this case,the brightness of the 1.3 μm micro-nanostructured coupled green QLED de-vice reaches 715 069 cd·m-2,and the maximum external quantum efficiency(EQE)and current efficiency are en-hanced to 12.5%and 57.3 cd·A-1.The individual electrical performances of the 1 μm-size-coupled blue QLED de-vice are nearly 200%improvement.The EQE of the 0.5 μm size-coupled red QLED device is also improved from 17.3%to 20.5%.And through the angular distribution test,it is proved that the micro-nano structure does not affect the luminous intensity of QLED devices,which is still close to the Lambertian emission.The solvent self-infiltration nanoimprinting process and QLED light extraction method proposed in this work provide a simple and effective way to improve the performance of QLEDs.
国家科技期刊平台
NSTL
万方数据
维普
