[17a-B6-1~9] 12.4 Organic light-emitting devices and organic transistors

9:00 AM - 9:15 AM JST(12:00 AM - 12:15 AM UTC)English Presentation

[17a-B6-1] Efficient Transparent Quantum-Dot Light-Emitting Diodes Using Polyethylenimine-Ethoxylated Buffer Layer

〇Mian Wei^1,2, Junyu Ren¹, Huaibin Shen¹ (1.Henan Univ., 2.UTokyo)

Keywords:

Transparent quantum dot-light-emitting diode,Sputtering Plasma Damage,All-solution-processed

Transparent quantum-dot light-emitting diodes (Tr-QLEDs) enabling the information display on transparent panels, making them well-suited for next-generation applications. ^[1] However, the performance of Tr-QLEDs has suffered from the damage to the functional layers caused by the conventional deposition process of the top transparent indium-tin-oxide (ITO) electrode. ^{[2, 3]}
Here, we present a solution to the issue of top electrode deposition damage by adding a non-toxic polyethylenimine-ethoxylated (PEIE) buffer layer between the top electrode and the underlying layers. Using this method, the resultant Tr-QLEDs with PEIE buffer layer demonstrated a maximum external quantum efficiency (EQE) improved from 10.6% to 17.1% for total light emission, including the bottom and top emissions, representing a 1.6-fold increase compared to the devices without PEIE layer. The maximum brightness (L) improved from 42290 cd m^-2 to 85120 cd m^-2. And the current efficiency (CE) enhanced from 11.77 cd A^-1 to 24.61 cd A^-1. The Tr-QLEDs also demonstrated a transmittance of 82% at 626 nm. Furthermore, the PEIE layer suppressed the excessive flow of electrons, leading to an improved carrier injection balance, resulting in low efficiency roll-off at high brightness levels, maintaining an EQE of 16% at a brightness of 40000 cd cm⁻². Our strategy holds great potential for developing high performance Tr-QLEDs.

References
[1] C. Luo et al., Adv. Mater. 35, 2303329 (2023).
[2] D. M. Mattox, J. Vac. Sci. Technol. A 7.1105 (1989).
[3] H. K. Kim et al., Appl. Phys. Lett. 86, 18 (2005).