Red Perovskite Light-emitting Diodes Based On Collaborative Optimization Of Emission Layer And Transport Layers

Metal halide perovskite light-emitting diode(PeLEDs)is a new type of semiconductor luminescent material is considered to be a popular material for the next generation of color display equipment.The charge recombination at the electrode interfaces and within the emission layer are the key factors restricting the performance of PeLEDs.And the efficiency of the current red light emitting devices is relatively mature compared with the development of green light device performance is still a big gap,so in order to achieve a high color gamut display devices must be optimized red perovskite LED.In this paper,respectively for lead and tin based perovskite devices to do the following work:1.In this work,the charge transport layers on both sides of the perovskite are optimized simultaneously to reduce the energy loss at the interfaces.Solution-processed aluminum-doped zinc oxide(AZO)nanoparticles are introduced as the electron transport layer in the traditional device structure,which effectively simplifies the device manufacturing process and greatly improves the device performance.Furthermore,an ultra-thin polymethyl methacrylate(PMMA)layer is introduced as a modified layer to reduce the exciton quenching between the hole transport layer and the perovskite emission layer.Poly(2-ethyl-2-oxazoline)(PEOX)is used as an additive to significantly enhance the solvent resistance of the perovskite layer.By collaborative optimization,a deep red PeLEDs emitting at 683 nm with a turn-on voltage of only 1.6 V and a maximum brightness of 7798 cd m-2 is achieved,providing a new idea for the development of high-performance all-solution-processed PeLEDs.2.In this chapter,we report the high efficiency lead-free(TEA)2SnI4 perovskite light-emitting device with color coordinates(0.698,0.301).By using biuret with strong coordination with Sn2+,the crystallization rate of perovskite can be slowed down,and the morphology of the film can be improved.The addition of biuret can also protect tin from oxidation in the film forming process.The efficiency roll-down of the device was reduced by using solution-treated molybdenum oxide nanoparticles as the hole transport layer.This work demonstrates the potential of cadmium-free and lead-free perovskite in display technology...