Inverted All-Inorganic Nanorod-Based Light-Emitting Diodes via Electrophoretic Deposition

Yongliang Zhang; Na Jia; Devika Laishram; Khizar Hussain Shah; Lin Lyu; Mei-Yan Gao; Pai Liu; Xiao Wei Sun; Tewfik Soulimane; Zhenhui Ma; Christophe Silien; Kevin M Ryan; Ning Liu

doi:10.1021/acsanm.4c03891

Inverted All-Inorganic Nanorod-Based Light-Emitting Diodes via Electrophoretic Deposition

ACS Appl Nano Mater. 2024 Oct 7;7(20):23617-23626. doi: 10.1021/acsanm.4c03891. eCollection 2024 Oct 25.

Authors

Affiliations

¹ Department of Physics and Bernal Institute, University of Limerick, Limerick V94 T9PX, Ireland.
² Department of Chemical Sciences and Bernal Institute, University of Limerick, Limerick V94 T9PX, Ireland.
³ Institute of Nanoscience and Applications, and Department of Electrical and Electronic Engineering, Southern University of Science and Technology, Shenzhen, Guangdong 518055, China.
⁴ Shenzhen Key Laboratory of Deep Subwavelength Scale Photonics, Southern University of Science and Technology, Shenzhen 518055, China.
⁵ Department of Physics, Beijing Technology and Business University, Beijing 100048, China.

Abstract

High performance and high stability in all-inorganic solution processed nanocrystal-based light-emitting diodes (LEDs) are highly attractive for large area devices compared to organic material-based LEDs. In this work, an inverted all-inorganic LED structure is designed to have an easy integration with thin-film transistors. Adopting robust inorganic materials such as Ni_1-x O nanoparticle films as a hole transport layer (HTL) is beneficial for the performance of LED. Herein, we have optimized the HTL by introducing Mg into Ni_1-x O to bridge the difference in energy offset between the nanorod emissive layer and the HTL, in addition to the advantages of low temperature solubility of Ni_1-x O:Mg nanoparticles. Furthermore, CdSe/CdS-based nanorods via electrophoretic deposition (EPD) are amassed in a vertically aligned (VA-NR) fashion as an emissive layer to facilitate the carrier transportation. Fostering these approaches enabled an EQE of 1.2% of the fabricated device, establishing the viability for further development of efficient and highly stable nanocrystal-based LEDs.