Enhanced Hole Injection Characteristics of a Top Emission Organic Light-Emitting Diode with Pure Aluminum Anode.

Chan Young Park,Byoungdeog Choi

doi:10.3390/nano11112869

Chan Young Park, Byoungdeog Choi

Open Access

https://doi.org/10.3390/nano11112869

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Journal: Nanomaterials (Basel, Switzerland)	Publication Date: Oct 27, 2021
Citations: 6	License type: CC BY 4.0

Affiliation: Sungkyunkwan University

Abstract

A top emitting organic light-emitting diode (OLED) device with pure aluminum (Al) anode for high-resolution microdisplays was proposed and fabricated. The low work function of the Al anode, even with a native oxide formed on the Al anode surface, increases the energy barrier of the interface between the anode and hole injection layer, and has poor hole-injection properties, which causes the low efficiency of the device. To enhance the hole-injection characteristics of the Al anode, we applied hexaazatriphenylene hexacarbonitrile (HATCN) as the hole-injection layer material. The proposed OLED device with a pure Al anode and native oxide on the anode surface improved efficiency by up to 35 cd/A at 1000 nit, which is 78% of the level of normal OLEDs with indium tin oxide (ITO) anode.

Highlights

Characteristics of a Top EmissionOrganic light-emitting diodes (OLEDs) are currently applied to display panels for smart phones, tablets, and TVs
This means that hole injection characteristics of the proposed organic light-emitting diode (OLED) device are enhanced by Al anode and HATCN hole-injection layer (HIL), even though an energy barrier exists between the Al anode and HATCN HIL
We investigated the characteristics of OLED devices with a reflective Al anode and

Summary

Introduction

Characteristics of a Top EmissionOrganic light-emitting diodes (OLEDs) are currently applied to display panels for smart phones, tablets, and TVs. OLEDs have a limited resolution caused by the fabrication method of pixel-patterning using a fine metal mask (FMM), which is a shadow mask with tiny holes for patterning pixels from evaporated organic materials. For a microdisplay, which has high resolution of over 2000 ppi, applied to Virtual Reality (VR) devices and Augmented Reality (AR) devices, the FMM fabrication method is unavailable because the hole size of FMM is smaller than 10 um. Another approach was used to fabricate OLED microdisplays, involving a separated backplane and OLED panel [2,3]. The backplane driving each pixel is made of a single crystal silicon wafer substrate with a complementary metal-oxide-semiconductor (CMOS)

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Conclusion