Nondestructive Direct Photolithography for Patterning Quantum Dot Films by Atomic Layer Deposition of ZnO. Issue 22 (8th July 2022)

• Record Type: Journal Article
• Authors: Lee, Joon Yup; Kim, Eun A; Han, Jisu; Choi, Yeong‐Ho; Hahm, Donghyo; Kang, Chi Jung; Bae, Wan Ki; Lim, Jaehoon; Cho, Seong‐Yong
• Is Part Of: Advanced materials interfaces. Volume 9:Issue 22(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-07-08
• Subjects: atomic layer deposition -- InP quantum dot -- patterning quantum dot films -- photolithography -- quantum dot‐based light emitting diodes; Materials science -- Periodicals; 620.11
• DOI: 10.1002/admi.202200835
• Languages: English
• ISSNs: 2196-7350

Abstract

Abstract: Colloidal quantum dot‐based light‐emitting diodes (QD‐LEDs) are one of the potential future self‐emissive displays owing to their large‐scale solution‐processibility and high color purity. For the industrial application of QD‐LEDs, high‐performance QD‐LED and high‐resolution patterning of quantum dot (QD) films are required. Photolithography is an ideal tool for patterning QD films. Previously, the high‐resolution patterning of QD films using direct photolithography by ultra‐thin atomic layer deposition of ZnO on the QD surface is reported. The patterning process is acceptable for Cd‐based QD films, but the photoresist severely deteriorates the photoluminescence (PL) intensity of InP‐based QD films owing to the presence of sulfonic groups in the photoactive compound. Herein, a non‐destructive direct photolithography process for QD film patterning using a negative photoresist that does not affect the PL intensities of Cd‐ and InP‐based QD films is reported. The effect of the photoresist is also verified by a PL lifetime study. Extremely bright Cd‐ and InP‐based QD films are successfully patterned using a softer photoresist, and micropatterning of InP‐based QD films is reported for the first time in this work using photolithography. A QD electroluminescence device is also successfully fabricated using the patterning method. Abstract : Nondestructive and direct photolithography‐based quantum dot (QD) film patterning is successfully done by employing a sulfonic group‐free photoresist. Previously, Cd‐based QD film is patterned by typical photolithography, but InP‐based QD film shows significant photoluminescence (PL) quenching during the patterning process. PL intensity of atomic layer deposited ZnO‐coated QD film is not significantly affected when the photoresist is coated.