Wide color gamut(WCG) backlight for liquid crystal display(LCD) utilizing white light-emitting diodes(LED) has attracted considerable attention for their high efficiency and color reduction.In this review,recent devel...Wide color gamut(WCG) backlight for liquid crystal display(LCD) utilizing white light-emitting diodes(LED) has attracted considerable attention for their high efficiency and color reduction.In this review,recent developments in crystal structure,luminescence and applications of phosphors for wide color gamut LED backlight are introduced.As novel red phosphors,Mn4+activate fluoride and aluminate phosphors are advanced in quantum efficiency,thermal quenching and color saturation for their characteristic spectrum with broad excitation band and linear emission.The crystal structure and fluorescence properties of Mn4+doped fluosilicate,fluorogermanate,fluotitanate,as well as Sr4 Al14O25,CaAl12O19 and BaMgAl10O17 phosphors are discussed in detail.A serial of narrow-band red-emitting Eu2+,Eu3+and Pr3+-doped nitride silicates and molybdate phosphors are also introduced.Rare-earth-doped oxynitride and silicate green-emitting phosphors have attracted more and more attention because of the wide excitation,narrow emission,high quenching temperature,high quantum efficiency,such as β-sialon:Eu2+,Ba3Si6O12N2:Eu2+,MSi2O2N2:Eu2+(M=Ca,Sr,Ba),y-AlON:Mn2+and Ca3Sc2Si3O12:Ce3+.All above phosphors demonstrate their adaptability in wide color gamut LCD display.Especially for Mn4+doped fluosilicate red phosphor and β-sialon:Eu2+green phosphor.To achieve an ultra-high color gamut in white LED backlight and against the OLED,innovative narrow-band-emission red and green phosphor materials with independent intellectual property rights are continuously pursed.展开更多
A switchable autostereoscopic 3-dimensional(3D) display device with wide color gamut is introduced in this paper. In conjunction with a novel directional quantum-dot(QD) backlight, the precise scanning control strateg...A switchable autostereoscopic 3-dimensional(3D) display device with wide color gamut is introduced in this paper. In conjunction with a novel directional quantum-dot(QD) backlight, the precise scanning control strategy, and the eye-tracking system, this spatial-sequential solution enables our autostereoscopic display to combine all the advantages of full resolution,wide color gamut, low crosstalk, and switchable 2D/3D. And also, we fabricated an autostereoscopic display prototype and demonstrated its performances effectively. The results indicate that our system can both break the limitation of viewing position and provide high-quality 3D images. We present two working modes in this system. In the spatial-sequential mode,the crosstalk is about 6%. In the time-multiplexed mode, the viewer should wear auxiliary and the crosstalk is about 1%,just next to that of a commercial 3D display(BENQ XL2707-B and View Sonic VX2268 WM). Additionally, our system is also completely compatible with active shutter glasses and its 3D resolution is same as its 2D resolution. Because of the excellent properties of the QD material, the color gamut can be widely extended to 77.98% according to the ITU-R recommendation BT.2020(Rec.2020).展开更多
We propose a narrow-band birefringent filter and its application in wide color gamut.The birefringent filter consists of five phase retarders and two polarizers,and it has both narrow band and high transmittance.In th...We propose a narrow-band birefringent filter and its application in wide color gamut.The birefringent filter consists of five phase retarders and two polarizers,and it has both narrow band and high transmittance.In the experiment,we fabricate the birefringent filter using quartz phase retarders and polarizers,and apply it in serval different displays.The color gamuts of displays are enhanced more than 30%NTSC(National Television System Committee),and the widest color gamuts that have been obtained are 126%NTSC in liquid crystal displays and 138%NTSC in organic light-emitting devices.Moreover,the deep blue light in spectrum of display can be reduced using the birefringent filter.The birefringent filter can be an efficient element to achieve wide color gamut display.展开更多
Chlorophylls and carotenoids are the main pigments in leaves of higher plants. They combine to give color to leaves. Based on the CIE1931 chromaticity coordinates of chlorophylls and cartotenoids, which were obtained ...Chlorophylls and carotenoids are the main pigments in leaves of higher plants. They combine to give color to leaves. Based on the CIE1931 chromaticity coordinates of chlorophylls and cartotenoids, which were obtained from their classical absorption spectra and the law of additive color mixing, the theoretical color gamut of higher plant leaves is determined. The theoretical prediction agrees well with our experimental results.展开更多
Structural colors with high saturation,large gamut,high resolution,and tunable color are expected in practical applications.This work explores the generation of tunable structural color based on transmission metasurfa...Structural colors with high saturation,large gamut,high resolution,and tunable color are expected in practical applications.This work explores the generation of tunable structural color based on transmission metasurfaces.The designed metasurfaces consist of rectangular nanoholes etched in silver film,which is deposited on the stretchable polydimethylsiloxane(PDMS)substrate.The smaller separation of adjacent nanoholes makes the resolution of metasurface reach 63,500 dpi.The color gamut of the nanostructures reaches 146.9%sRGB.We also perform a comparison with the case on the glass substrate and analyze the incident polarization condition and the coating film of polymethyl methacrylate(PMMA).The ultra-thin structure,high resolution,highperformance structural colors,and convenient transmission mode provide broad application prospects for metasurfaces in color displaying,color printing,and color holographic imaging.展开更多
High-performance white light-emitting diodes (WLEDs) hold great potential for the next-generation backlight display applications.However,achieving highly efficient and stable WLEDs with wide-color-gamut has remained a...High-performance white light-emitting diodes (WLEDs) hold great potential for the next-generation backlight display applications.However,achieving highly efficient and stable WLEDs with wide-color-gamut has remained a formidable goal.Reported here is the first example of pure red narrow bandwidth emission triangular CQDs (PR-NBE-T-CQDs) with photoluminescence peaking at 610 nm.The PR-NBE-T-CQDs synthesized from resorcinol show high quantum yield (QY) of 72% with small full width at half maximum of 33 nm.By simply controlling the reaction time,pure green (PG-) NBE-T-CQDs with high QY of 75% were also obtained.Highly efficient and stable WLEDs with wide-color-gamut based on PR- and PG-NBE-T-CQDs was achieved.This WLED showed a remarkable wide-color gamut of 110% NTSC and high power efficiency of 86.5 lumens per Watt.Furthermore,such WLEDs demonstrate outstanding stability.This work will set the stage for developing highly efficient,low cost and environment-friendly WLEDs based on CQDs for the next-generation wide-color gamut backlight displays.展开更多
In this study,we analyze how a backlight’s peak wavelength,full-width at half-maximum(FWHM),and color filters affect the color gamut of a liquid crystal display(LCD)device and establish a theoretical limit,even if th...In this study,we analyze how a backlight’s peak wavelength,full-width at half-maximum(FWHM),and color filters affect the color gamut of a liquid crystal display(LCD)device and establish a theoretical limit,even if the FWHM approaches 1 nm.To overcome this limit,we propose a new backlight system incorporating a functional reflective polarizer and a patterned half-wave plate to decouple the polarization states of the blue light and the green/red lights.As a result,the crosstalk between three primary colors is greatly suppressed,and the color gamut is significantly widened.In the experiment,we prepare a white-light source using a blue light-emitting diode(LED)to pump green perovskite polymer film and red quantum dots and demonstrate an exceedingly large color gamut(95.8%Rec.2020 in Commission internationale de l'éclairage(CIE)1931 color space and 97.3%Rec.2020 in CIE 1976 color space)with commercial high-efficiency color filters.These results are beyond the color gamut limit achievable by a conventional LCD.Our design works equally well for other light sources,such as a 2-phosphorconverted white LED.展开更多
Regarding objects of monotonic emissivities in the visible waveband, the concept of color-kernel body is put forward. With this concept, the luminous color of actual objects is found out to be the mixture of the radia...Regarding objects of monotonic emissivities in the visible waveband, the concept of color-kernel body is put forward. With this concept, the luminous color of actual objects is found out to be the mixture of the radiative colors of a blackbody and a color-kernel body with different weights. The locus of the isothermal radiative colors is a straight-line segment in the chromaticity diagram. The whole color gamut of continuous emissions is about 17% of the entire gamut of natural colors and at its bottom.展开更多
Researchers and designers who work with color displays often transform color gamut between two different display devices. This paper demonstrates the effect of quantization error on the transformation based on analyzi...Researchers and designers who work with color displays often transform color gamut between two different display devices. This paper demonstrates the effect of quantization error on the transformation based on analyzing the color gamut deviation profoundly.展开更多
基金Project supported by National Key Research and Development Program(2017YFB0404301)
文摘Wide color gamut(WCG) backlight for liquid crystal display(LCD) utilizing white light-emitting diodes(LED) has attracted considerable attention for their high efficiency and color reduction.In this review,recent developments in crystal structure,luminescence and applications of phosphors for wide color gamut LED backlight are introduced.As novel red phosphors,Mn4+activate fluoride and aluminate phosphors are advanced in quantum efficiency,thermal quenching and color saturation for their characteristic spectrum with broad excitation band and linear emission.The crystal structure and fluorescence properties of Mn4+doped fluosilicate,fluorogermanate,fluotitanate,as well as Sr4 Al14O25,CaAl12O19 and BaMgAl10O17 phosphors are discussed in detail.A serial of narrow-band red-emitting Eu2+,Eu3+and Pr3+-doped nitride silicates and molybdate phosphors are also introduced.Rare-earth-doped oxynitride and silicate green-emitting phosphors have attracted more and more attention because of the wide excitation,narrow emission,high quenching temperature,high quantum efficiency,such as β-sialon:Eu2+,Ba3Si6O12N2:Eu2+,MSi2O2N2:Eu2+(M=Ca,Sr,Ba),y-AlON:Mn2+and Ca3Sc2Si3O12:Ce3+.All above phosphors demonstrate their adaptability in wide color gamut LCD display.Especially for Mn4+doped fluosilicate red phosphor and β-sialon:Eu2+green phosphor.To achieve an ultra-high color gamut in white LED backlight and against the OLED,innovative narrow-band-emission red and green phosphor materials with independent intellectual property rights are continuously pursed.
基金Project supported by the National Key R&D Program of China(Grant No.2016YFB0401503)the R&D Plan of Jiangsu Science and Technology Department,China(Grant No.BE2016173)
文摘A switchable autostereoscopic 3-dimensional(3D) display device with wide color gamut is introduced in this paper. In conjunction with a novel directional quantum-dot(QD) backlight, the precise scanning control strategy, and the eye-tracking system, this spatial-sequential solution enables our autostereoscopic display to combine all the advantages of full resolution,wide color gamut, low crosstalk, and switchable 2D/3D. And also, we fabricated an autostereoscopic display prototype and demonstrated its performances effectively. The results indicate that our system can both break the limitation of viewing position and provide high-quality 3D images. We present two working modes in this system. In the spatial-sequential mode,the crosstalk is about 6%. In the time-multiplexed mode, the viewer should wear auxiliary and the crosstalk is about 1%,just next to that of a commercial 3D display(BENQ XL2707-B and View Sonic VX2268 WM). Additionally, our system is also completely compatible with active shutter glasses and its 3D resolution is same as its 2D resolution. Because of the excellent properties of the QD material, the color gamut can be widely extended to 77.98% according to the ITU-R recommendation BT.2020(Rec.2020).
基金the National Natural Science Foundation of China(Grant Nos.61475042,11304074,and 11274088)the Natural Science Foundation of Hebei Province,China(Grant Nos.A2015202320 and GCC2014048).
文摘We propose a narrow-band birefringent filter and its application in wide color gamut.The birefringent filter consists of five phase retarders and two polarizers,and it has both narrow band and high transmittance.In the experiment,we fabricate the birefringent filter using quartz phase retarders and polarizers,and apply it in serval different displays.The color gamuts of displays are enhanced more than 30%NTSC(National Television System Committee),and the widest color gamuts that have been obtained are 126%NTSC in liquid crystal displays and 138%NTSC in organic light-emitting devices.Moreover,the deep blue light in spectrum of display can be reduced using the birefringent filter.The birefringent filter can be an efficient element to achieve wide color gamut display.
基金This work is supported by the Foundation of the China National Natural Sciences (Grant No.59006487)the Special Foundationfor Doctoral Programof the Ministry of Education (Grant No.97035821)
文摘Chlorophylls and carotenoids are the main pigments in leaves of higher plants. They combine to give color to leaves. Based on the CIE1931 chromaticity coordinates of chlorophylls and cartotenoids, which were obtained from their classical absorption spectra and the law of additive color mixing, the theoretical color gamut of higher plant leaves is determined. The theoretical prediction agrees well with our experimental results.
基金National Natural Science Foundation of China(10874105)Natural Science Foundation of Shandong Province(ZR2020KA009)。
文摘Structural colors with high saturation,large gamut,high resolution,and tunable color are expected in practical applications.This work explores the generation of tunable structural color based on transmission metasurfaces.The designed metasurfaces consist of rectangular nanoholes etched in silver film,which is deposited on the stretchable polydimethylsiloxane(PDMS)substrate.The smaller separation of adjacent nanoholes makes the resolution of metasurface reach 63,500 dpi.The color gamut of the nanostructures reaches 146.9%sRGB.We also perform a comparison with the case on the glass substrate and analyze the incident polarization condition and the coating film of polymethyl methacrylate(PMMA).The ultra-thin structure,high resolution,highperformance structural colors,and convenient transmission mode provide broad application prospects for metasurfaces in color displaying,color printing,and color holographic imaging.
基金supported by the National Natural Science Foundation of China (NSFC)(Nos.21573019 and 21872010)the Major Research Plan of the National Natural Science Foundation of China (No.21233003)the Fundamental Research Funds for the Central Universities.
文摘High-performance white light-emitting diodes (WLEDs) hold great potential for the next-generation backlight display applications.However,achieving highly efficient and stable WLEDs with wide-color-gamut has remained a formidable goal.Reported here is the first example of pure red narrow bandwidth emission triangular CQDs (PR-NBE-T-CQDs) with photoluminescence peaking at 610 nm.The PR-NBE-T-CQDs synthesized from resorcinol show high quantum yield (QY) of 72% with small full width at half maximum of 33 nm.By simply controlling the reaction time,pure green (PG-) NBE-T-CQDs with high QY of 75% were also obtained.Highly efficient and stable WLEDs with wide-color-gamut based on PR- and PG-NBE-T-CQDs was achieved.This WLED showed a remarkable wide-color gamut of 110% NTSC and high power efficiency of 86.5 lumens per Watt.Furthermore,such WLEDs demonstrate outstanding stability.This work will set the stage for developing highly efficient,low cost and environment-friendly WLEDs based on CQDs for the next-generation wide-color gamut backlight displays.
基金Guanjun Tan for helpful discussions and AFOSR for partial financial support under contract No.FA9550-14-1-0279.
文摘In this study,we analyze how a backlight’s peak wavelength,full-width at half-maximum(FWHM),and color filters affect the color gamut of a liquid crystal display(LCD)device and establish a theoretical limit,even if the FWHM approaches 1 nm.To overcome this limit,we propose a new backlight system incorporating a functional reflective polarizer and a patterned half-wave plate to decouple the polarization states of the blue light and the green/red lights.As a result,the crosstalk between three primary colors is greatly suppressed,and the color gamut is significantly widened.In the experiment,we prepare a white-light source using a blue light-emitting diode(LED)to pump green perovskite polymer film and red quantum dots and demonstrate an exceedingly large color gamut(95.8%Rec.2020 in Commission internationale de l'éclairage(CIE)1931 color space and 97.3%Rec.2020 in CIE 1976 color space)with commercial high-efficiency color filters.These results are beyond the color gamut limit achievable by a conventional LCD.Our design works equally well for other light sources,such as a 2-phosphorconverted white LED.
文摘Regarding objects of monotonic emissivities in the visible waveband, the concept of color-kernel body is put forward. With this concept, the luminous color of actual objects is found out to be the mixture of the radiative colors of a blackbody and a color-kernel body with different weights. The locus of the isothermal radiative colors is a straight-line segment in the chromaticity diagram. The whole color gamut of continuous emissions is about 17% of the entire gamut of natural colors and at its bottom.
文摘Researchers and designers who work with color displays often transform color gamut between two different display devices. This paper demonstrates the effect of quantization error on the transformation based on analyzing the color gamut deviation profoundly.
