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Your search keyword '"Wong, Kam Sing"' showing total 14 results
Start Over Author "Wong, Kam Sing" Journal advanced optical materials
14 results on '"Wong, Kam Sing"'

2. Heterocyclic Diammonium Dion‐Jacobson Perovskite Blue Light‐Emitting Diodes with Nonshift Emission Peak Under High Bias Voltage

Author

Zou, Shibing, primary, Fan, Kezhou, additional, Wu, Xiao, additional, Yuan, Ligang, additional, Wang, Jiarong, additional, Wang, Kangyang, additional, Li, Jiong, additional, Wei, Jianwu, additional, Xu, Shuang, additional, Zou, Feilin, additional, Wong, Kam Sing, additional, Lu, Xinhui, additional, Xu, Jianbin, additional, and Yan, Keyou, additional

Published
2024
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3. Strongly Confined and Spectrally Tunable CsPbBr3 Quantum Dots for Deep Blue QD‐LEDs.

Author

Ding, Pengbo, Ko, Pui Kei, Geng, Pai, Chen, Dezhang, Xing, Zengshan, Tsang, Hoi Lam Tammy, Wong, Kam Sing, Guo, Liang, and Halpert, Jonathan E.

Subjects
QUANTUM dots, QUANTUM efficiency, LIGHT emitting diodes, EMISSION control, ELECTRON traps, PEROVSKITE, PHOTOLUMINESCENCE
Abstract

Despite recent advances, it is still difficult to fabricate deep blue‐emitting perovskite light‐emitting diodes (LEDs) that are immune to the color instability caused by halide mixing. This is largely because it is still challenging to achieve bright, stable, pure bromide perovskite materials with deep blue emission. Here, a novel strategy is reported for synthesizing ultrasmall CsPbBr3 quantum dots (QDs) under ambient conditions. Precise size control is used to tune the peak emission wavelengths, via the confinement effect, from 433 to 501 nm. These ultrasmall QDs, with sizes of 2–6 nm, exhibit ultralow trap density and stable photoluminescence quantum yields up to 94%, particularly in the deep blue spectral region (440–465 nm). QD‐LEDs fabricated with these materials achieve an external quantum efficiency of 1.0% at 459 nm. The exceptional control of the emission properties demonstrated here suggests a new strategy for building stable, efficient blue QD‐LEDs. [ABSTRACT FROM AUTHOR]

Published
2024
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6. Enhanced Light Emission Performance of Mixed Cation Perovskite Films—The Effect of Solution Stoichiometry on Crystallization

Author

Liu, Fangzhou, primary, Qin, Xinshun, additional, Han, Bing, additional, Chan, Christopher C. S., additional, Ma, Chao, additional, Leung, Tik Lun, additional, Chen, Wei, additional, He, Yanling, additional, Lončarić, Ivor, additional, Grisanti, Luca, additional, Ovčar, Juraj, additional, Skoko, Željko, additional, Shi, Yingli, additional, Ling, Francis Chi Chung, additional, Huqe, Md Rashedul, additional, Zapien, Juan Antonio, additional, Wang, Shixun, additional, Su, Chun‐Jen, additional, Jeng, U‐Ser, additional, Wong, Kam Sing, additional, Ng, Alan Man Ching, additional, Gu, Meng, additional, Popović, Jasminka, additional, and Djurišić, Aleksandra B., additional

Published
2021
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7. Enhanced Electrochemical Stability by Alkyldiammonium in Dion–Jacobson Perovskite toward Ultrastable Light‐Emitting Diodes

Author

Ngai, Kwan Ho, primary, Wei, Qi, additional, Chen, Zefeng, additional, Guo, Xinlu, additional, Qin, Minchao, additional, Xie, Fangyan, additional, Chan, Christopher Chang Sing, additional, Xing, Guichuan, additional, Lu, Xinhu, additional, Chen, Jian, additional, Wong, Kam Sing, additional, Xu, Jianbin, additional, and Long, Mingzhu, additional

Published
2021
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8. Mixed Spacer Cation Stabilization of Blue‐Emitting n = 2 Ruddlesden–Popper Organic–Inorganic Halide Perovskite Films

Author

Leung, Tik Lun, primary, Tam, Ho Won, additional, Liu, Fangzhou, additional, Lin, Jingyang, additional, Ng, Alan Man Ching, additional, Chan, Wai Kin, additional, Chen, Wei, additional, He, Zhubing, additional, Lončarić, Ivor, additional, Grisanti, Luca, additional, Ma, Chao, additional, Wong, Kam Sing, additional, Lau, Ying Suet, additional, Zhu, Furong, additional, Skoko, Željko, additional, Popović, Jasminka, additional, and Djurišić, Aleksandra B., additional

Published
2019
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9. Ruddlesden–Popper Perovskites: Spontaneous Formation of Nanocrystals in Amorphous Matrix: Alternative Pathway to Bright Emission in Quasi‐2D Perovskites (Advanced Optical Materials 19/2019)

Author

Liu, Fangzhou, primary, Chan, Christopher Chang Sing, additional, Ma, Chao, additional, Tam, Ho Won, additional, Leung, Tik Lun, additional, Lin, Jingyang, additional, Djurišić, Aleksandra B., additional, Wong, Kam Sing, additional, Popović, Jasminka, additional, Ng, Alan Man Ching, additional, Chan, Wai Kin, additional, Chen, Wei, additional, He, Zhubing, additional, Adesina, Ayotunde Emmanuel, additional, Foo, Yishu, additional, and Zapien, Juan Antonio, additional

Published
2019
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10. Spontaneous Formation of Nanocrystals in Amorphous Matrix: Alternative Pathway to Bright Emission in Quasi‐2D Perovskites

Author

Liu, Fangzhou, primary, Chan, Christopher Chang Sing, additional, Ma, Chao, additional, Tam, Ho Won, additional, Leung, Tik Lun, additional, Lin, Jingyang, additional, Djurišić, Aleksandra B., additional, Wong, Kam Sing, additional, Popović, Jasminka, additional, Ng, Alan Man Ching, additional, Chan, Wai Kin, additional, Chen, Wei, additional, He, Zhubing, additional, Adesina, Ayotunde Emmanuel, additional, Foo, Yishu, additional, and Zapien, Juan Antonio, additional

Published
2019
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11. Mixed Spacer Cation Stabilization of Blue‐Emitting n = 2 Ruddlesden–Popper Organic–Inorganic Halide Perovskite Films.

Author

Leung, Tik Lun, Tam, Ho Won, Liu, Fangzhou, Lin, Jingyang, Ng, Alan Man Ching, Chan, Wai Kin, Chen, Wei, He, Zhubing, Lončarić, Ivor, Grisanti, Luca, Ma, Chao, Wong, Kam Sing, Lau, Ying Suet, Zhu, Furong, Skoko, Željko, Popović, Jasminka, and Djurišić, Aleksandra B.

Subjects
PEROVSKITE, CATIONS, HALIDES, HIGH temperature physics
Abstract

Ruddlesden–Popper halide perovskite (RPP) materials are of significant interest for light‐emitting devices since their emission wavelength can be controlled by tuning the number of layers n, resulting in improved spectral stability compared to mixed halide devices. However, RPP films typically contain phases with different n, and the low n phases tend to be unstable upon exposure to humidity, irradiation, and/or elevated temperature which hinders the achievement of pure blue emission from n = 2 films. In this work, two spacer cations are used to form an RPP film with mixed cation bilayer and high n = 2 phase purity, improved stability, and brighter light emission compared to a single spacer cation RPP. The stabilization of n = 2 phase is attributed to favorable formation energy, reduced strain, and reduced electron–phonon coupling compared to the RPP films with only one type of spacer cation. Using this approach, pure blue light‐emitting diodes (LEDs) with Commission Internationale de l'éclairage (CIE) coordinates of (0.156, 0.088) and excellent spectral stability are achieved. [ABSTRACT FROM AUTHOR]

Published
2020
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