123rd General Meeting of the KCS

Type Poster Presentation
Area Material Chemistry
Room No. Exhibition Hall 2
Time 4월 19일 (금요일) 11:00~12:30
Code MAT.P-437
Subject Guanidinium-Incorporated Cesium Lead Halide Perovskite for Green-Light-Emitting Diodes
Authors Wonhee Cha, Dongho Kim1,*
Chemistry, Yonsei University, Korea
1Department of Chemistry, Yonsei University, Korea
Abstract Organic-inorganic lead halide perovskites have attracted much attention as promising candidates for photovoltaics (PVs), light-emitting diodes (LEDs), and lasing materials due to their excellent optical and electronic properties, high color purity, and their widely tunable emission wavelength. Cesium (Cs)-based lead halide perovskites have received much attention as light emitting materials due to their excellent photoelectronic properties. Despites the high efficiency for light emitting diodes (LEDs), only a few cesium lead bromide (CsPbBr3) perovskite-based devices have been developed due to the low stabilities and/or the formation of undesirable phase under ambient condition. Herein, it is demonstrated that a small quantity of guanidinium (GUA) A-site cation addition results in enhanced photoluminescence and improved crystallinity of the perovskite films. A GUA-incorporated multi-dimensional quasi-2D film with higher photoluminescence quantum yield (~20%) than Cs-only 3D perovskite film (~10%) was employed in a green-LED device with an inverted structure of glass substrate/indium tin oxide (ITO)/zinc oxide (ZnO)/poly(ethyleneimine) (PEI)/perovskite/poly(4-butylphenyl-diphenyl-amine) (poly-TPD)/WO3/Al. With an addition of GUA A-site cation, we achieved much higher brightness and current efficiency of ~10000 cd m-2 and 9.0 cd/A in the LEDs of perovskite thin film as compared to Cs-only perovskite thin film LEDs with ~400 cd m-2 and 0.2 cd/A.
E-mail wonhee900416@yonsei.ac.kr