[6p-A203-1~19] 12.4 Organic light-emitting devices and organic transistors

▼ [6p-A203-7] Single-crystal MAPbBr₃ based flexible light-emitting diodes prepared by cast-capping method

〇(DC)Cao Van Nguyen¹, Hiroyuki Katsuki¹, Fumio Sasaki², Hisao Yanagi¹ (1.NAIST, 2.AIST)

Keywords:Perovskite, Cast-capping method, LED

Low cost and flexible devices are demands of next optoelectronic generation devices. Recently, perovskites have become promising materials due to their attractive properties for solar cells and light emitting devices with tunable emission wavelengths, long carries life time and low-temperature processing. Here we present “single-crystal” MAPbBr₃ based flexible light-emitting diodes prepared by cast-capping method. This method includes two simple processes: casting a precursor perovskites solution on a substrate and capping with another substrate. Then, large-sized single cubic crystals were formed between the substrates.
We first fabricated a very simple flexible LED: ITO/MAPbBr₃/ITO where ITO coated-PET substrates were used to make flexible electrodes. After dryness for few days, single-crystal MAPbBr₃ with few-μm thickness was grown between the ITO-PET electrodes. Secondary, LEDs with PET/ITO/ZnO/MAPbBr₃/MoO₃/ITO/PET structure was built. ZnO and MoO₃ films were used as electron and hole transport layers, respectively. The ZnO thin film was prepared by the sol-gel method with zinc acetate dissolved in methanol to give 1.5 mg/mL concentration. The ZnO solution was spin-coated on the ITO/PET substrate and annealed at 100^oC for 12 hours. The MoO₃ film (~10 nm thick) was vapor-deposition on another ITO/PET substrate.