Atomic Layer Deposition for Quantum Dots Displays’ Devices Stabilization

Abstract

As display plays an increasingly important role in people's life, from mobile phones, automobile displays to AR, VR and 3D naked eye screens. There are increasing demands for pursuing higher resolution, refresh frequency, wider color gamut, etc. Therefore, photoluminescence materials with excellent photoelectric performance have attracted broad attention, but there are still some problems in their application, and achieving higher performance with stability is still urgent to be solved. Atomic layer deposition (ALD) has been developed as an attractive method to modify and stabilize photoluminescence materials. For photoluminescence PL performance, the stabilization of crystal structure can be achieved by solution treatment, and the luminescence performance can be improved. ALD was performed to enhance the stability of CsPbBr3 quantum dots in light, water and heat, which originated from the surface defects passivation. The combined method of organic hydrophobic surface modification and ALD infiltration is used to construct a dual-shelled to prevent the crystal deformation and ligand desorption of luminescent materials, and is also applicable to phosphor materials. For electroluminescence EL performance, ALD modification methods were developed for the light-emitting layer modifying, gas phase ALD and colloidal ALD were developed to decreasing the transport barrier between the quantum dots, improve the carrier mobility of the device, and lift the EQE and stability of the device. In addition, ultrathin film grow through ALD could effectively balance the carrier and improve the recombination efficiency as well as important functional layers. ALD of dual Electron transport layers(ETLs) and dual hole injection layers(HILs) is developed to enhance luminance performance of the PQLEDs but also achieve a long lifetime under constant voltage. Our works provide a versatile method for preparing ultra stable photoluminescence materials through ALD and significantly improve their potential in LED illumination and displays.