Reversible, Full-Color Luminescence by Post-treatment of Perovskite Nanocrystals

Yoon, Yung Jin; Lee, Jun Young; Lee, Tae Kyung; Kim, Su Hwan; Shin, Yun Seop; Walker, Bright; Park, Song Yi; Heo, Jungwoo; Lee, Junghoon; Kwak, Sang Kyu; Kim, Gi-Hwan; Kim, Jin Young

doi:10.1016/j.joule.2018.07.012

Cited by 65 publications

(45 citation statements)

References 25 publications

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“…Among the different forms of MHP, nanocrystals (NCs) of MHP are emerging as one of the most exciting optoelectronic materials by virtue of their excellent photophysical properties including tunable, direct bandgap [4], strong quantum confinement [5], high photoluminescence quantum yield [6,7], and tolerance to defects [8] to name a few. Thanks to the advancement in material engineering of perovskite NCs in terms of morphology, stoichiometric control, doping, and surface treatment [9][10][11][12][13][14], highperformance light-emitting devices with external quantum efficiency (EQE) of 23.4% and 23.0% have been achieved with MHP NCs for green and red emission, respectively [15,16]. Nevertheless, most of the peak efficiencies are often observed at relatively low current densities and correspondingly low brightness due to lack of surface protection [17].…”

Section: Introductionmentioning

confidence: 99%

Surface Treatment of Inorganic CsPbI3 Nanocrystals with Guanidinium Iodide for Efficient Perovskite Light-Emitting Diodes with High Brightness

et al. 2022

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The remarkable evolution of metal halide perovskites in the past decade makes them promise for next-generation optoelectronic material. In particular, nanocrystals (NCs) of inorganic perovskites have demonstrated excellent performance for light-emitting and display applications. However, the presence of surface defects on the NCs negatively impacts their performance in devices. Herein, we report a compatible facial post-treatment of CsPbI3 nanocrystals using guanidinium iodide (GuI). It is found that the GuI treatment effectively passivated the halide vacancy defects on the surface of the NCs while offering effective surface protection and exciton confinement thanks to the beneficial contribution of iodide and guanidinium cation. As a consequence, the film of treated CsPbI3 nanocrystals exhibited significantly enhanced luminescence and charge transport properties, leading to high-performance light-emitting diode with maximum external quantum efficiency of 13.8% with high brightness (peak luminance of 7039 cd m−2 and a peak current density of 10.8 cd A−1). The EQE is over threefold higher than performance of untreated device (EQE: 3.8%). The operational half-lifetime of the treated devices also was significantly improved with T50 of 20 min (at current density of 25 mA cm−2), outperforming the untreated devices (T50 ~ 6 min).

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Section: Introductionmentioning

confidence: 99%

Surface Treatment of Inorganic CsPbI3 Nanocrystals with Guanidinium Iodide for Efficient Perovskite Light-Emitting Diodes with High Brightness

et al. 2022

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“…Particularly, the PeQD‐X can change the bandgap even after the completion of synthesis by exchanging halide anions, thereby rendering the PeQD‐X suitable for LEDs. [ 7,8 ] Nedelcu et al. reported that the photoluminescence (PL) emission (red, green, and blue colors) of PeQD‐X solutions can be determined based on the ratio of halide anions.…”

Section: Introductionmentioning

confidence: 99%

All‐in‐One Process for Color Tuning and Patterning of Perovskite Quantum Dot Light‐Emitting Diodes

et al. 2022

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Although post-synthetic anion exchange allows halide perovskite quantum dots to easily change the optical bandgap of materials, additional exchange of shorter ligands is required to use them as active materials in optoelectronic devices. In this study, a novel all-in-one process exchanging ligands and halide anions in film-state for facile color tuning and patterning of cesium lead halide perovskite colloidal quantum dot (PeQD) light-emitting diodes (LEDs) is proposed. The proposed all-in-one process significantly enhances the performances of PeQD LEDs by passivating the PeQD with shorter ligands. In addition, the all-in-one process is repeated more stably in the film state. Red, green, and blue LEDs with extremely narrow emission spectra using cesium lead bromide PeQDs and appropriate butylammonium halide solutions are fabricated. Furthermore, the proposed all-in-one process in film-state facilitated rapid color change in localized areas, thereby aiding in realizing fine patterns of narrow widths (300 μm) using simple contact masks. Consequently, various paint-over red/green/blue patterns in PeQD LEDs by applying halide solutions additively are fabricated.

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“…In this study, we demonstrated a high quantum efficiency with distinguishable blue-emitting regions of 480, 470, and 460 nm using mixed-halide ion-pair ligands, di-dodecyl dimethyl ammonium bromide (DDAB) and di-dodecyl dimethyl ammonium chloride (DDAC) . For the blue emissions, the high amount of Cl anions is a critical problem in CsPbCl 3 NCs owing to their low stability. , Therefore, using chloride ions (Cl – ) induced from a ligand of DDAC, stable CsPbX 3 NCs can be reconstructed through a self-anion exchange based on the unique property of perovskite . Using this treatment, perovskite NCs showed a finely tuned emission wavelength toward the deep-blue region at near 460 nm with a passivation of the surface defect states through a coordination bonding with Cs + or Pb + , which are positively charged metals.…”

Section: Introductionmentioning

confidence: 99%

Vivid and Fully Saturated Blue Light-Emitting Diodes Based on Ligand-Modified Halide Perovskite Nanocrystals

Shin

Yoon

Lee

et al. 2019

ACS Appl. Mater. Interfaces

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CsPbX3 (X = I, Br, Cl) perovskite nanocrystals (NCs) have recently emerged as emitting materials for optoelectronic and display applications owing to their easily tunable emissions, high photoluminescence quantum yield (PLQY), and vivid color purity (full width at half maximum of approximately 20 nm). However, the lagging quantum yields of blue-emitting perovskite NCs have resulted in low efficiency compared to green or red perovskite light-emitting diodes (PeLEDs); moreover, the long insulating ligands (such as oleylamine and oleic acid) inhibit charge carrier injection. In this study, we demonstrated a facile ligand-mediated post-treatment (LMPT) method for high-quality perovskite NCs with changing optical properties to allow fine-tuning of the target emission wavelength. This method involves the use of a mixed halide ion-pair ligand, di-dodecyl dimethyl ammonium bromide, and chloride, which can induce a reconstruction through a self-anion exchange. Using the LMPT method, the PLQY of the surface-passivated blue-emitting NCs was dramatically enhanced to over 70% within the 485 nm blue emission region and 50% within the 467 nm deep-blue emission region. Through this treatment, we achieved highly efficient blue-PeLED maximum external quantum efficiencies of 0.44 and 0.86% within the 470 and 480 ± 2 nm electroluminescence emission regions, respectively.

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Reversible, Full-Color Luminescence by Post-treatment of Perovskite Nanocrystals

Cited by 65 publications

References 25 publications

Surface Treatment of Inorganic CsPbI3 Nanocrystals with Guanidinium Iodide for Efficient Perovskite Light-Emitting Diodes with High Brightness

Surface Treatment of Inorganic CsPbI3 Nanocrystals with Guanidinium Iodide for Efficient Perovskite Light-Emitting Diodes with High Brightness

All‐in‐One Process for Color Tuning and Patterning of Perovskite Quantum Dot Light‐Emitting Diodes

Vivid and Fully Saturated Blue Light-Emitting Diodes Based on Ligand-Modified Halide Perovskite Nanocrystals

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