Enhancing the Efficiency of Color Conversion Micro-LED Display with a Patterned Cholesteric Liquid Crystal Polymer Film
Color-converted micro-light-emitting diode (micro-LED) displays with wide color gamut, high ambient contrast ratio, and fast response time are emerging as a potentially disruptive technology. However, due to limited optical density and thickness of the color-conversion film, the blue light leakage a...
| Main Authors: | , , , , , , , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2020-12-01
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| Series: | Nanomaterials |
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| Online Access: | https://www.mdpi.com/2079-4991/10/12/2430 |
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| author | En-Lin Hsiang Yannanqi Li Ziqian He Tao Zhan Caicai Zhang Yi-Fen Lan Yajie Dong Shin-Tson Wu |
| author_facet | En-Lin Hsiang Yannanqi Li Ziqian He Tao Zhan Caicai Zhang Yi-Fen Lan Yajie Dong Shin-Tson Wu |
| author_sort | En-Lin Hsiang |
| collection | DOAJ |
| description | Color-converted micro-light-emitting diode (micro-LED) displays with wide color gamut, high ambient contrast ratio, and fast response time are emerging as a potentially disruptive technology. However, due to limited optical density and thickness of the color-conversion film, the blue light leakage and low color-conversion efficiency still hinder their widespread applications. In this paper, we demonstrate a patterned cholesteric liquid crystal (CLC) polymer film with two special optical functionalities. On the green and red sub-pixels, the corresponding planar CLC texture acts as a distributed Bragg reflector for the blue light, which in turn improves the color conversion efficiency and expands the color gamut. On the blue sub-pixels, the corresponding focal-conic CLC texture acts as light scattering medium, which helps to reduce the angular color shift. Further analysis reveals that the patterned CLC film can alleviate the crosstalk between green and blue color filters. Therefore, compared to the display system without such a CLC film, our proposed device structure increases the color conversion efficiency by 143% (at ~90% Rec. 2020) and reduces average angular color shift Δu’v’ from 0.03 to 0.018 at the viewing angle with the most severe color shift. Such a patterned CLC film is applicable to all kinds of color-conversion display systems, including organic and inorganic phosphors. |
| first_indexed | 2024-03-10T14:18:21Z |
| format | Article |
| id | doaj.art-51907e7ffda84cbab670e890ee3d036a |
| institution | Directory Open Access Journal |
| issn | 2079-4991 |
| language | English |
| last_indexed | 2024-03-10T14:18:21Z |
| publishDate | 2020-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Nanomaterials |
| spelling | doaj.art-51907e7ffda84cbab670e890ee3d036a2023-11-20T23:36:03ZengMDPI AGNanomaterials2079-49912020-12-011012243010.3390/nano10122430Enhancing the Efficiency of Color Conversion Micro-LED Display with a Patterned Cholesteric Liquid Crystal Polymer FilmEn-Lin Hsiang0Yannanqi Li1Ziqian He2Tao Zhan3Caicai Zhang4Yi-Fen Lan5Yajie Dong6Shin-Tson Wu7College of Optics and Photonics, University of Central Florida, Orlando, FL 32816, USACollege of Optics and Photonics, University of Central Florida, Orlando, FL 32816, USACollege of Optics and Photonics, University of Central Florida, Orlando, FL 32816, USACollege of Optics and Photonics, University of Central Florida, Orlando, FL 32816, USADepartment of Materials Science & Engineering, University of Central Florida, Orlando, FL 32816, USAAU Optronics Corp., Hsinchu Science Park, Hsinchu 300, TaiwanCollege of Optics and Photonics, University of Central Florida, Orlando, FL 32816, USACollege of Optics and Photonics, University of Central Florida, Orlando, FL 32816, USAColor-converted micro-light-emitting diode (micro-LED) displays with wide color gamut, high ambient contrast ratio, and fast response time are emerging as a potentially disruptive technology. However, due to limited optical density and thickness of the color-conversion film, the blue light leakage and low color-conversion efficiency still hinder their widespread applications. In this paper, we demonstrate a patterned cholesteric liquid crystal (CLC) polymer film with two special optical functionalities. On the green and red sub-pixels, the corresponding planar CLC texture acts as a distributed Bragg reflector for the blue light, which in turn improves the color conversion efficiency and expands the color gamut. On the blue sub-pixels, the corresponding focal-conic CLC texture acts as light scattering medium, which helps to reduce the angular color shift. Further analysis reveals that the patterned CLC film can alleviate the crosstalk between green and blue color filters. Therefore, compared to the display system without such a CLC film, our proposed device structure increases the color conversion efficiency by 143% (at ~90% Rec. 2020) and reduces average angular color shift Δu’v’ from 0.03 to 0.018 at the viewing angle with the most severe color shift. Such a patterned CLC film is applicable to all kinds of color-conversion display systems, including organic and inorganic phosphors.https://www.mdpi.com/2079-4991/10/12/2430micro-LED displayperovskite nanocrystalscholesteric liquid crystalwide color gamutcolor conversion efficiency |
| spellingShingle | En-Lin Hsiang Yannanqi Li Ziqian He Tao Zhan Caicai Zhang Yi-Fen Lan Yajie Dong Shin-Tson Wu Enhancing the Efficiency of Color Conversion Micro-LED Display with a Patterned Cholesteric Liquid Crystal Polymer Film Nanomaterials micro-LED display perovskite nanocrystals cholesteric liquid crystal wide color gamut color conversion efficiency |
| title | Enhancing the Efficiency of Color Conversion Micro-LED Display with a Patterned Cholesteric Liquid Crystal Polymer Film |
| title_full | Enhancing the Efficiency of Color Conversion Micro-LED Display with a Patterned Cholesteric Liquid Crystal Polymer Film |
| title_fullStr | Enhancing the Efficiency of Color Conversion Micro-LED Display with a Patterned Cholesteric Liquid Crystal Polymer Film |
| title_full_unstemmed | Enhancing the Efficiency of Color Conversion Micro-LED Display with a Patterned Cholesteric Liquid Crystal Polymer Film |
| title_short | Enhancing the Efficiency of Color Conversion Micro-LED Display with a Patterned Cholesteric Liquid Crystal Polymer Film |
| title_sort | enhancing the efficiency of color conversion micro led display with a patterned cholesteric liquid crystal polymer film |
| topic | micro-LED display perovskite nanocrystals cholesteric liquid crystal wide color gamut color conversion efficiency |
| url | https://www.mdpi.com/2079-4991/10/12/2430 |
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