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Highly Stable and Scalable Blue QD-LED via an Evaporated TiO2 Thin Film as an Electron Transport Layer

Accepted version
Peer-reviewed

Type

Article

Change log

Authors

Fan, XB 
Jung, SM 
Yang, J 
Shin, DW 

Abstract

jats:titleAbstract</jats:title>jats:pQuantum dot‐based light‐emitting diodes (QD‐LEDs) have excellent optical properties; however, their limitations of stability, reproducibility, and scalability due to the solution process are the major drawback. Herein, blue QD‐LEDs fabricated with the conventional vacuum process using an e‐beam‐evaporated TiOjats:sub2</jats:sub> thin film as an electron transport layer (ETL) are demonstrated. CdZnS/ZnS‐based blue LEDs with a TiOjats:sub2</jats:sub> thin film are fabricated under ambient conditions. They exhibit maximum external quantum efficiencies of 3.53% and a peak luminance of 2847 cd mjats:sup−2</jats:sup>. These values are retained, which minimizes performance degradation under high potential bias. In addition, the optimized evaporated TiOjats:sub2</jats:sub> thin film has a negligible red shift (0.5 nm) of the peak wavelength between the photoluminescence spectrum and electroluminescence spectrum with stable full‐width at half‐maximum changing by less than 2 nm at high voltage. Finally, a blue QD‐LED is fabricated on a scalable emission area of 2 × 2 in. with a patterned cathode accompanied by an evaporated TiOjats:sub2</jats:sub> thin film, which allows to perform conventional photolithography. A highly stable and reproducible vaporized inorganic thin film as the ETL supports the multilayer architecture to minimize the process damage.</jats:p>

Description

Keywords

e-beam evaporator, light-emitting diodes, metal oxide thin films, quantum dots, scalable optoelectronics

Journal Title

Advanced Optical Materials

Conference Name

Journal ISSN

2195-1071
2195-1071

Volume Title

8

Publisher

Wiley

Rights

All rights reserved
Sponsorship
EPSRC (EP/P027628/1)
European Commission Horizon 2020 (H2020) Research Infrastructures (RI) (685758)
Engineering and Physical Sciences Research Council (EP/P027628/1)