Control of carrier injection and transport in quantum dot light emitting diodes (QLEDs) via modulating Schottky injection barrier and carrier mobility

Interfacial electronic structure between W-doped In2O3 and V2O5 has been investigated, and we found gap states that can provide an efficient hole carrier injection pathway.

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Solution-Processed Smooth Copper Thiocyanate Layer with Improved Hole Injection Ability for the Fabrication of Quantum Dot Light-Emitting Diodes

Nanomaterials ◽

10.3390/nano12010154 ◽

2022 ◽

Vol 12 (1) ◽

pp. 154

Author(s):

Ming-Ru Wen ◽

Sheng-Hsiung Yang ◽

Wei-Sheng Chen

Keyword(s):

Quantum Dot ◽

Current Efficiency ◽

Light Emitting Diodes ◽

Hole Mobility ◽

Environmental Stability ◽

Hole Injection ◽

Visible Range ◽

Carrier Injection ◽

High Brightness ◽

Light Emitting

Copper thiocyanate (CuSCN) has been gradually utilized as the hole injection layer (HIL) within optoelectronic devices, owing to its high transparency in the visible range, moderate hole mobility, and desirable environmental stability. In this research, we demonstrate quantum dot light-emitting diodes (QLEDs) with high brightness and current efficiency by doping 2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane (F4TCNQ) in CuSCN as the HIL. The experimental results indicated a smoother surface of CuSCN upon F4TCNQ doping. The augmentation in hole mobility of CuSCN and carrier injection to reach balanced charge transport in QLEDs were confirmed. A maximum brightness of 169,230 cd m−2 and a current efficiency of 35.1 cd A−1 from the optimized device were received by adding 0.02 wt% of F4TCNQ in CuSCN, revealing promising use in light-emitting applications.

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Influence of the Carrier Mobility and Charge Accumulation in Interfacial Layers on Deterioration in Organic Light-emitting Diodes

IEEJ Transactions on Fundamentals and Materials ◽

10.1541/ieejfms.137.291 ◽

2017 ◽

Vol 137 (5) ◽

pp. 291-297

Author(s):

Hirofumi Nakamura ◽

Miki Kuribayashi ◽

Chihaya Adachi

Keyword(s):

Carrier Mobility ◽

Light Emitting Diodes ◽

Organic Light Emitting Diodes ◽

Charge Accumulation ◽

Light Emitting ◽

Interfacial Layers ◽

Organic Light

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Injecting Inter-Layers and the Built-in Potential of Blue Polymer Light-Emitting Diodes

MRS Proceedings ◽

10.1557/proc-660-jj6.9 ◽

2000 ◽

Vol 660 ◽

Author(s):

Thomas M. Brown ◽

Ian S. Millard ◽

David J. Lacey ◽

Jeremy H. Burroughes ◽

Richard H. Friend ◽

...

Keyword(s):

Indium Tin Oxide ◽

Light Emitting Diodes ◽

Basic Structure ◽

Thin Layers ◽

Carrier Injection ◽

Semiconducting Polymer ◽

Light Emitting ◽

Physical Mechanisms ◽

Organic Solid ◽

Polymer Light Emitting Diodes

ABSTRACTThe semiconducting-polymer/injecting-electrode heterojunction plays a crucial part in the operation of organic solid state devices. In polymer light-emitting diodes (LEDs), a common fundamental structure employed is Indium-Tin-Oxide/Polymer/Al. However, in order to fabricate efficient devices, alterations to this basic structure have to be carried out. The insertion of thin layers, between the electrodes and the emitting polymer, has been shown to greatly enhance LED performance, although the physical mechanisms underlying this effect remain unclear. Here, we use electro-absorption measurements of the built-in potential to monitor shifts in the barrier height at the electrode/polymer interface. We demonstrate that the main advantage brought about by inter-layers, such as poly(ethylenedioxythiophene)/poly(styrene sulphonic acid) (PEDOT:PSS) at the anode and Ca, LiF and CsF at the cathode, is a marked reduction of the barrier to carrier injection. The electro- absorption results also correlate with the electroluminescent characteristics of the LEDs.

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