CsPbBr3 Perovskite Quantum Dot Light‐Emitting Diodes Using Atomic Layer Deposited Al2O3 and ZnO Interlayers. Issue 1 (31st October 2019)

• Record Type: Journal Article
• Authors: Yun, Hwang-Sik; Noh, Kyeongchan; Kim, Jigeon; Noh, Sung Hoon; Kim, Gi-Hwan; Lee, Woongkyu; Na, Hyon Bin; Yoon, Tae-Sik; Jang, Jaeyoung; Kim, Younghoon; Cho, Seong-Yong
• Is Part Of: Physica status solidi. Volume 14:Issue 1(2020)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2019-10-31
• Subjects: atomic layer deposition -- interlayers -- light-emitting diodes -- perovskites -- quantum dots; Solid state physics -- Periodicals; 530.4105
• DOI: 10.1002/pssr.201900573
• Languages: English
• ISSNs: 1862-6254

Abstract

Abstract : Most CsPbBr3 perovskite quantum dot light‐emitting diodes (PQD‐LEDs) are fabricated with an inverted device structure where hole transport/injection layers are vacuum‐deposited on top of ITO/ZnO (as an electron transport layer (ETL))/PQDs. Standard device architecture of PQD‐LEDs enables a solution‐process of device fabrication; however, the spin‐coating of ZnO ETL dissolved in polar solvent results in decreasing photoluminescence (PL) of PQDs because of PQD destabilization in polar medium. Herein, CsPbBr3 PQD‐LEDs are fabricated by depositing Al2 O3 and ZnO via atomic layer deposition (ALD) to avoid damages originating from the polar solvent during ZnO ETL spin‐coating. Low temperature ALD is adopted to prevent the coarsening of the CsPbBr3 PQDs. A thicker Al2 O3 interlayer can prevent PL quenching, but an excessively thick interlayer hinders electron transport due to the insulating nature of Al2 O3 . ZnO is sequentially deposited on Al2 O3 interlayer via ALD, and therefore Al2 O3 /ZnO bilayer structure is used because of its better electron transporting ability and higher power efficiency in PQD‐LED devices compared with Al2 O3 ‐only devices. Abstract : Green emitting CsPbBr3 perovskite quantum dot light‐emitting diodes (PQD‐LEDs) are fabricated in a standard device structure with insertion of atomic‐layer deposited interlayer. This interlayer enables deposition of solution‐processed ZnO nanoparticles on top of CsPbBr3 PQDs directly, and successfully passivate PQD surface from polar solvent damages during ZnO spin‐casting.