Challenges and Opportunities for the Blue Perovskite Quantum Dot Light-Emitting Diodes

Weng, Shuchen; Yu, Guicheng; Zhou, Chao; Lin, Fang; Han, Yonglei; Wang, Hao; Huang, Xiaoxi; Liu, Xiaoyuan; Hu, Hanlin; Liu, Wei; Wang, Yongfei; Lin, Haoran

doi:10.3390/cryst12070929

Cited by 11 publications

(3 citation statements)

References 56 publications

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“…[2][3][4][5][6] Despite these impressive improvements, several issues impede widespread commercialization, such as stability, lead toxicity, and spectral efficiency in the blue region of the visible spectrum. [7][8][9] This latter effect is due to the chloride-perovskites being far from defect tolerant, resulting in extremely poor efficiencies compared to bromide-and iodide-based perovskites. [10] Another way to tune the spectral response in PNCs is through quantum confinement.…”

Section: Introductionmentioning

confidence: 99%

Rapid Data‐Efficient Optimization of Perovskite Nanocrystal Syntheses through Machine Learning Algorithm Fusion

et al. 2023

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With the demand for renewable energy and efficient devices rapidly increasing, a need arises to find and optimize novel (nano)materials. With sheer limitless possibilities for material combinations and synthetic procedures, obtaining novel, highly functional materials has been a tedious trial and error process. Recently, machine learning has emerged as a powerful tool to help optimize syntheses; however, most approaches require a substantial amount of input data, limiting their pertinence. Here, three well‐known machine‐learning models are merged with Bayesian optimization into one to optimize the synthesis of CsPbBr3 nanoplatelets with limited data demand. The algorithm can accurately predict the photoluminescence emission maxima of nanoplatelet dispersions using only the three precursor ratios as input parameters. This allows us to fabricate previously unobtainable seven and eight monolayer‐thick nanoplatelets. Moreover, the algorithm dramatically improves the homogeneity of 2–6‐monolayer‐thick nanoplatelet dispersions, as evidenced by narrower and more symmetric photoluminescence spectra. Decisively, only 200 total syntheses are required to achieve this vast improvement, highlighting how rapidly material properties can be optimized. The algorithm is highly versatile and can incorporate additional synthetic parameters. Accordingly, it is readily applicable to other less‐explored nanocrystal syntheses and can help rapidly identify and improve exciting compositions’ quality.

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Section: Introductionmentioning

confidence: 99%

Rapid Data‐Efficient Optimization of Perovskite Nanocrystal Syntheses through Machine Learning Algorithm Fusion

et al. 2023

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“…Song et al first proposed the blue PQLEDs using CsPbCl x Br 3−x PQDs synthesized by a traditional hot-injection method, achieving an EQE of 0.07% [24]. Subsequently, various strategies have been presented to improve the device performance of the blue PQLEDs [25]. The surface-ligand exchange methods were commonly used to decrease the surface defeat of PQDs, improve stability and enhance charge injection [26][27][28][29][30][31].…”

Section: Introductionmentioning

confidence: 99%

Anion-Exchange Blue Perovskite Quantum Dots for Efficient Light-Emitting Devices

et al. 2022

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In this study, blue perovskite quantum dots (PQDs) were prepared using didodecyldimethylammonium bromide (DDAB), which can passivate surface defects caused by the loss of surface ligands and reduce particle size distribution. After the passivation of DDAB, blue CsPbClxBr3−x PQDs dispersed in n-octane produced a more compact and uniform PQD thin film than the non-passivated ones. The resulting device showed a stabile lifetime, and an EL peak of 470 nm and a maximum EQE of 1.63% were obtained at an operating voltage of 2.6 V and a current density of 0.34 mA/cm2. This work aims to provide a simple method to prepare blue-emitting PQDs and high-performance PQD-based light-emitting devices.

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“…These include solution processability, high defect tolerance, tunable bandgap, high photoluminescence quantum yield (PLQY), and vivid color saturation. − Remarkable strides have been made in the development of pure red and green perovskite-based LEDs, achieving efficiencies surpassing 20%. − However, the efficiency of blue LEDs, especially those aiming for a pure blue LED toward display devices, lags significantly behind their red and green counterparts. Currently, sky blue light (∼490 nm) perovskite LEDs have been reported with efficiencies exceeding 15%. , Nevertheless, as the wavelength decreases toward pure blue, ranging between 465 and 475 nm, a notable decline in device efficiency is observed. − The primary challenges faced by pure blue perovskite LEDs are low efficiency, short lifetime, and poor spectral stability. These issues primarily stem from the challenging electrical injection resulting from the wide bandgap and efficiency loss caused by high-density deep traps. − Consequently, the development of high-quality pure blue perovskite emitters with low defects and minimal traps is crucial for achieving efficient and stable pure blue perovskite LEDs.…”

mentioning

confidence: 99%

Eliminating Chlorine Vacancies of Perovskite Nanocrystals Using Hydrazine Cations Enables Efficient Pure Blue Light-Emitting Diodes

Ma,

Li,

et al. 2024

ACS Energy Lett.

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Mixed Br/Cl-perovskite nanocrystals (Pe-NCs) CsPbBr x Cl 3−x , synthesized at room temperature (RT), offer several advantages for use in light-emitting diodes (LEDs), including cost-effective processing and a narrow luminescence peak. However, achieving efficient pure blue LEDs using CsPbBr x Cl 3−x NCs has been proven to be challenging due to a significant number of chlorine defects. In this work, we propose a passivation strategy utilizing hydrazine cations (Hz 2+ ) to eliminate chlorine defects in RT-synthesized Pe-NCs. Our investigation reveals that Hz 2+ can capture the isolated chlorine anion (Cl − ) to form a Hz−Cl−Cs bridge on the Pe-NC surface, thereby effectively inhibiting the formation of chlorine vacancies. This approach significantly enhances both the photoluminescence efficiency and lifetime of Pe-NCs. Consequently, LEDs fabricated using Hz 2+ -passivated Pe-NCs achieve an outstanding external quantum efficiency (EQE) of 7.82% at 475 nm. Our findings highlight an effective passivation strategy that significantly mitigates chlorine defects in Pe-NCs, thereby advancing the development of efficient pure blue LEDs.

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Challenges and Opportunities for the Blue Perovskite Quantum Dot Light-Emitting Diodes

Cited by 11 publications

References 56 publications

Rapid Data‐Efficient Optimization of Perovskite Nanocrystal Syntheses through Machine Learning Algorithm Fusion

Rapid Data‐Efficient Optimization of Perovskite Nanocrystal Syntheses through Machine Learning Algorithm Fusion

Anion-Exchange Blue Perovskite Quantum Dots for Efficient Light-Emitting Devices

Eliminating Chlorine Vacancies of Perovskite Nanocrystals Using Hydrazine Cations Enables Efficient Pure Blue Light-Emitting Diodes

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