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|
| Type |
Symposium |
| Area |
Frontier of Materials Chemistry: Photosciences |
| Room No. |
Room 322 |
| Time |
FRI 14:55-: |
| Code |
MAT2-2 |
| Subject |
Next-Generation Light Emitters: Halide Perovskite Light-emitting Diodes
|
| Authors |
Tae-Woo Lee
Department of Materials Science and Engineering, Seoul National University, Korea |
| Abstract |
Metal halide perovskites have emerged as promising next-generation light emitter due to their advantages such as high luminescence efficiency, high color purity, low material cost, solution processability, high charge-carrier mobility, and defect-tolerant electronic structure. Nevertheless, the low electroluminescence (EL) efficiency of perovskite light-emitting diodes (PeLEDs) at room temperature has been a big challenge which should be overcome. Here, we present high-efficiency PeLEDs using various strategies to overcome the EL efficiency limitations. First, we demonstrated a self-organized buffer hole injection layer to reduce the hole injection barrier and suppress the exciton quenching at the interface. Also, we showed that the formation of metallic lead clusters can cause strong exciton quenching and non-radiative recombination, which was prevented by finely increasing the molar proportion of methylammonium bromide (MABr) in MAPbBr3 solution. Further, the EL efficiency could be dramatically enhanced by decreasing the size of MAPbBr3 grains with improved uniformity and coverage of MAPbBr3 layers. High-efficiency flexible MAPbBr3 PeLEDs has been also demonstrated by using ideal anodes including graphene and ITO-free polymeric anode materials, which boosted the highest EQE up to 10.93% for pure green PeLEDs. We also developed mixed-cation systems with new substitute cations for MA using stable formamidinium (FA) and cesium (Cs), demonstrating first highly efficient and stable polycrystalline PeLEDs based on mixed cations. Furthermore, we developed efficient quasi-2D PeLEDs using Ruddlesden-Popper phase formed by incorporation of long alkyl cations and precise control over layered 2D structures. |
| E-mail |
twlees@snu.ac.kr |
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122nd General Meeting of the KCS