共查询到20条相似文献,搜索用时 31 毫秒
1.
Ji‐Guang Li Zhihao Wang Qi Zhu Zhixin Xu Xuejiao Wang Byung‐Nam Kim Xiaodong Li Xudong Sun 《Journal of the American Ceramic Society》2018,101(10):4519-4525
Uniform spheres of (Yb0.98RE0.02)PO4 orthophosphate (RE=Ho, Er, and Tm, respectively) were synthesized via a homogeneous precipitation procedure mediated by SO42? anions. The as‐precipitated and 1100°C calcined products were determined via laser‐diffraction particle sizing to have the average diameters of ~2.04 ± 0.67 and 1.80 ± 0.93 μm, respectively. The upconversion luminescence of RE3+ under sensitization by the host Yb3+ was studied for the calcination products under 978 nm laser excitation, and it was found that the emissions are dominated by a red band at ~650 nm for Ho3+ (5F5 → 5I8 transition), similarly strong green (~515‐565 nm, 2H11/2/4S3/2 → 4I15/2 transition) and red (~640‐680 nm, 4F9/2 → 4I15/2 transition) bands for Er3+, and a near‐infrared band at ~800 nm for Tm3+ (3H4 → 3H6 transition). The number of laser photons needed to populate the emitting state was determined by varying the excitation power, and the possible photon reactions leading to the observed upconversion were discussed. 相似文献
2.
Garnet-type Li6Ca(La0.97Yb0.02RE0.01)2Nb2O12 (RE = Ho, Er, Tm) new phosphors were successfully synthesized via solid reaction at 900°C for 5 hours, whose course of phase evolution, macroscopic/local crystal structure and up-/down-conversion (UC/DC) photoluminescence were clarified. Mechanistic study and materials characterization were attained via XRD, Rietveld refinement, DTA/TG, electron microscopy (FE-SEM/TEM), and Raman/reflectance/fluorescence spectroscopies. The phosphors were shown to exhibit UC luminescence dominated by a ~ 553 nm green band (5F4/5S2 → 5I8 transition) for Ho3+, a ~ 568 nm green band (4S3/2 → 4I15/2 transition) for Er3+ and a ~ 806 nm near-infrared band (3H4 → 3H6 transition) for Tm3+ under 978 nm laser excitation, with CIE chromaticity coordinates of around (0.31, 0.68), (0.38, 0.60) and (0.17, 0.24), respectively. Analysis of the pump-power dependence of UC intensity indicated that all the emissions involve a two-photon mechanism except for the ~ 486 nm blue emission of Tm3+ (1G4 → 3H6), which requires a three-photon process. The DC luminescence of these phosphors is featured by dominant bands at ~ 553 nm for Ho3+ (green, 5F4/5S2 → 5I8 transition), ~568 nm for Er3+ (green, 4S3/2 → 4I15/2 transition) and ~ 464 nm for Tm3+ (blue, 1D2 → 3F4 transition). The UC and DC properties were also comparatively discussed. 相似文献
3.
Xiaoni Wang Ting Li Wenchao Liang Chunchun Zhu Liandong Guo 《Journal of the American Ceramic Society》2021,104(11):5826-5836
Up-conversion luminescent (UCL) materials are excellent candidate for optical anti-counterfeiting and the exploitation of multi-wavelength NIR light triggered UC phosphors with tunable color emission is essential for reliable anti-counterfeiting technology. Herein, a series of lanthanide ions (Er3+, Er3+–Ho3+, and Yb3+–Tm3+) doped BaTiO3 submicrometer particles are synthesized through a modified hydrothermal procedure. XRD and SEM measurements were carried out to identify the structure and morphology of the samples and their UCL properties under 808, 980, and 1550 nm NIR excitation are investigated. Er3+ singly doped sample exhibits Er3+ concentration-dependent and excitation wavelength-dependent emission color from green to yellow and orange. The corresponding UC mechanisms under three NIR light excitation are clarified. Pure red emission under 1550-nm excitation was obtained by introducing small amount of Ho3+ and the fluorescent lifetime test was used to confirm the energy transfer from Er3+ to Ho3+. In addition, Yb3+–Tm3+ co-doped sample shows intense blue emission from 1G4 → 3H6 transition of Tm3+ under 980-nm excitation. As a proof of concept, the designed pattern using phosphors with red, green, and blue three primary color emissions under 1550, 808, and 980 nm NIR excitation was displayed to demonstrate their anti-counterfeiting application. 相似文献
4.
BaCl2:Er3+—A High Efficient Upconversion Phosphor for Broadband Near‐Infrared Photoresponsive Devices
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Zhi Chen Hong Jia Xiaowen Zhang Jianmin Liu Shengfeng Zeng Yang Li Zhijun Ma Guoping Dong Jianrong Qiu 《Journal of the American Ceramic Society》2015,98(8):2508-2513
Utilization of photons with subband‐gap energy, mostly near‐infrared (NIR) photons, is highly desirable for photovoltaic cells; which can be achieved by adding an upconversion layer at the rear face of photovoltaic cells. Here, we study the upconversion luminescence properties of BaCl2:Er3+ phosphors and hexagonal NaYF4:Er3+ phosphors upon excitation of incoherent NIR sunlight with wavelength λ > 800 nm. Higher efficacious upconversion emissions of BaCl2:Er3+ phosphors have been observed in comparison with the well‐known hexagonal NaYF4:Er3+ phosphors. We demonstrate that the photocurrent response from the thin‐film‐hydrogenated amorphous silicon solar cell attached with the BaCl2:Er3+ phosphor is notably enhanced under irradiation of incoherent NIR sunlight with wavelength λ > 800 nm. This judicious design may be envisioned to shorten the distance for the remarkable improvement of the power conversion efficiency of the next‐generation photovoltaic cells and suggests a promising application for other NIR photoresponsive devices. 相似文献
5.
Li2SrSiO4:Ce3+, Pr3+ Phosphor with Blue,Red, and Near‐Infrared Emissions Used for Plant Growth LED
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Jiayu Chen Chongfeng Guo Zheng Yang Ting Li Jin Zhao 《Journal of the American Ceramic Society》2016,99(1):218-225
Ce3+/Pr3+ codoped Li2SrSiO4 (LSS) phosphors with blue, red, and near‐infrared (NIR) tri‐emission have been prepared via a high‐temperature solid‐state reaction method. Under the excitation of 200 to 400 nm near‐ultraviolet (n‐UV), the photoluminescence (PL) spectra of phosphors are composed of visible and NIR two parts. The former exhibits blue and red emission bands centered at around 428 nm from 5d–4f transition of Ce3+ and 611 nm from 1D2 → 3H4 transition of Pr3+, those overlap with photosynthesis action spectra of plants and absorption spectra of chlorophylls and carotenoids. While the later presents a broad NIR emission band peaking near 1039 nm caused by the 1G4 → 3H4 of Pr3+, matching with the absorption of bacteriochlorophyll. Their emission intensity ratios (B: R: NIR) could be tuned by altering the relative ratios of Ce3+ and Pr3+ concentration in the phosphors to meet the requirements of multifarious plants and bacteria. The efficient energy transfer from Ce3+ to Pr3+ takes place in the LSS host, which ascribed to an exchange interaction according to PL spectra and decay curves of phosphors. Results suggest that the present LSS: Ce3+, Pr3+ phosphors have great potential applications in plant growth n‐UV LED. 相似文献
6.
Yunfeng Jiang Rensheng Shen Xiangping Li Jinsu Zhang Hua Zhong Yue Tian Jiashi Sun Lihong Cheng Haiyang Zhong Baojiu Chen 《Ceramics International》2012,38(6):5045-5051
Ho3+/Yb3+ co-doped NaGdTiO4 phosphors were synthesized by a solid-state reaction method. The upconversion (UC) luminescence characteristics excited by 980 nm laser diode were systematically investigated. Bright green UC emission centered at 551 nm accompanied with weak red and near infrared (NIR) UC emissions centered at 652 and 761 nm were observed. The dependence of UC emission intensity on excitation power density showed that all of green, red and NIR UC emissions are involved in two-photon process. The UC emission mechanisms were discussed in detail. Concentration dependence studies indicated that Ho3+ and Yb3+ concentrations had significant influences on UC luminescence intensity and the intensity ratio of the red UC emission to that of the green one. Rate equations were established based on the possible UC mechanisms and a theoretical formula was proposed to describe the concentration dependent UC emission. The UC luminescence properties of the presented material was evaluated by comparing with commercial NaYF4:Er3+, Yb3+ phosphor, and our sample showed a high luminescence efficiency and good color performance, implying potential applications in a variety of fields. 相似文献
7.
《Ceramics International》2022,48(1):824-831
The Cr3+ doped Zn3Ga2Ge2O10 long persistent phosphor materials were synthesized by solid state reaction method. The crystal structure of the synthesized phosphors are cubic with space group Fd3m. The band gap of the undoped host is about 4.48 eV. The materials show three photoluminescence excitation bands peaked at 260 nm, 412 nm and 580 nm. Due to the broad excitation band, the phosphors can be excited by UV light or visible light or sunlight. The phosphors shows a photoluminescence emission band peaked at 698 nm when excited by UV light. The afterglow emission shows a broad emission band with maximum at 700 nm. The detection of NIR light from the sample was observed by Night Vision Monocular for 24 h after switch off the excitation source. A mechanism is introduced to describe afterglow phenomenon and trap depth was calculated from thermoluminescence curve. As the material emit NIR persistent light, it was used as a secret light source for night vision devices. The developed material was used for tagging, tracking and locating purposes in defence application. The acrylic based paint was prepared to develop long persistent near infrared (NIR) paint, which can be coated on combat vehicle, ship, weapon, helmet, cloth, tent, rock for defence application. The NIR security ink was prepared and demonstrated to prevent counterfeit. Encryption and decryption method of confidential information was presented by using NIR security ink. 相似文献
8.
Optical Temperature Sensing Behavior of High‐Efficiency Upconversion: Er3+–Yb3+ Co‐Doped NaY(MoO4)2 Phosphor
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Xingxing Yang Zuoling Fu Yanmin Yang Chunpeng Zhang Zhijian Wu Tianqi Sheng 《Journal of the American Ceramic Society》2015,98(8):2595-2600
A class of Yb3+/Er3+ co‐doped NaY(MoO4)2 upconversion (UC) phosphors have been successfully synthesized by a facile hydrothermal route with further calcination. The structural properties and the phase composition of the samples were characterized by X‐ray diffraction (XRD). The UC luminescence properties of Yb3+/Er3+ co‐doped NaY(MoO4)2 were investigated in detail. Concentration‐dependent studies revealed that the optimal composition was realized for a 2% Er3+ and 10% Yb3+‐doping concentration. Two‐photon excitation UC mechanism further illustrated that the green enhancement arised from a novel energy‐transfer (ET) pathway which entailed a strong ground‐state absorption of Yb3+ ions and the excited state absorption of Yb3+–MoO42? dimers, followed by an effective energy transfer to the high‐energy state of Er3+ ions. We have also studied the thermal properties of UC emissions between 303 and 523 K for the optical thermometry behavior under a 980 nm laser diode excitation for the first time. The higher sensitivity for temperature measurement could be obtained compared to the previous reported rare‐earth ions fluorescence based optical temperature sensors. These results indicated that the present sample was a promising candidate for optical temperature sensors with high sensitivity. 相似文献
9.
Intense upconversion luminescence and energy‐transfer mechanism of Ho3+/Yb3+ co‐doped SrLu2O4 phosphor
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Songbin Liu Xinyu Ye Shuifu Liu Mengyao Chen Hu Niu Dejian Hou Weixiong You 《Journal of the American Ceramic Society》2017,100(8):3530-3539
A series of novel SrLu2O4: x Ho3+, y Yb3+ phosphors (x=0.005‐0.05, y=0.1‐0.6) were synthesized by a simple solid‐state reaction method. The phase purity, morphology, and upconversion luminescence were measured by X‐ray diffraction (XRD), scanning electron microscopy (SEM), and photoluminescence (PL) spectroscopy. The doping concentrations and sintering temperature were optimized to be x=0.01, y=0.5 and T=1400°C to obtain the strongest emission intensity. Under 980 nm laser diode excitation, the SrLu2O4:Ho3+, Yb3+ phosphors exhibit intense green upconversion (UC) emission band centered at 541 nm (5F4,5S2→5I8) and weak red emission peaked at 673 nm (5F5→5I8). Under different pump‐power excitation, the UC luminescence can be finely tuned from yellow‐green to green light region to some extent. Based on energy level diagram, the energy‐transfer mechanisms are investigated in detail according to the analysis of pump‐power dependence and luminescence decay curves. The energy‐transfer mechanisms for green and red UC emissions can be determined to be two‐photon absorption processes. Compared with commercial NaYF4:Er3+, Yb3+ and common Y2O3:Ho3+, Yb3+ phosphors, the SrLu1.49Ho0.01Yb0.5O4 sample shows good color monochromaticity and relatively high UC luminescence intensity. The results imply that SrLu2O4:Ho3+, Yb3+ can be a good candidate for green UC material in display fields. 相似文献
10.
《Ceramics International》2023,49(20):33316-33323
Y2O3: x% Er3+ (x=5, 7, 10, 12, 15) and Y2O3: 10% Er3+,x% K+ (x=0, 1, 3, 5, 7, 10, 15) phosphors were successfully prepared by a low-temperature combustion method. The structure as well as the absorption/emission spectra of phosphors were investigated. The effect of doping concentration of K+ ions on the upconversion (UC) luminescence of Y2O3: 10% Er3+ phosphor was examined and the possible optical transitions were discussed. The results showed that K+ ion doping not only changed the microstructure and crystallinity of the phosphors, but also enhanced its UC luminescence intensity. The Y2O3: 10% Er3+, 7% K+ phosphor exhibit the strongest UC emission intensity. Compared with the Y2O3: 10% Er3+ phosphor, the UC luminescence intensity at 563 nm and 661 nm was enhanced by 67.8 and 27.3 times for the K-codoped samples, respectively. The phosphor with the optimal doping concentration was mixed with a polymer to form a composite film, which was employed for the fabrication of near-infrared (NIR) photo-responsive detection devices. The device exhibited strong photo-current response to NIR light at 980 nm, implying that our work could inspire new design strategy for the development of NIR photo-detection devices. 相似文献
11.
Meidan Que ZhiPeng Ci Yuhua Wang Ge Zhu Bitao Liu Jia Zhang YuRong Shi Yan Wen Yao Li Qian Wang 《Journal of the American Ceramic Society》2013,96(1):223-227
A new chlorogermanate compound Ca8Mg(GeO4)4Cl2 (CMGC) was synthesized via high‐temperature solid‐state reaction for the first time. The crystal structure of CMGC had been refined and determined from the XRD profiles by Rietveld refinement method, which belong to space group Fd‐3m with the lattice constants a = b = c = 15.1760(25) Å. Photoluminescence properties of CMGC:Eu2+ phosphors were investigated by absorption spectra, excitation, and emission spectra. The occupy situation and energy transfer were investigated by decay lifetimes and emission spectra under different excitation wavelengths. Thermal stability was also measured. The results show that the absorption spectra of CMGC:Eu2+ phosphors cover from 250 to 500 nm. Under 365 and 435 nm excitation, the emission spectra of CMGC:Eu2+ phosphors show blue‐green (centered at 425 and 510 nm) and green (centered at 510 nm) emission, respectively, which attributed to Eu2+ ions occupying different crystal sites. Our results indicated that CMGC:Eu2+ phosphors had a potential application use for white light‐emitting diodes. 相似文献
12.
Energy‐Transfer Modulation for Enhanced Photocatalytic Activity of Near‐Infrared Upconversion Photocatalyst
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Binbin Zheng Qiangbing Guo Di Wang Hao Zhang Yifei Zhu Shifeng Zhou 《Journal of the American Ceramic Society》2015,98(1):136-140
One of the major challenges of near‐infrared upconversion photocatalyst concerns strengthening the cooperation between Rare‐earth (RE) ions and semiconductor materials for enhancing NIR photocatalytic activity. Herein, the basic energy‐transfer (ET) process between RE ions and semiconductor materials is discussed and the appropriate mode, nonradiative ET, is proposed for efficiently coupling them. As an example, a novel NIR‐based UC photocatalyst, CaIn2O4:Yb3+,Tb3+ was designed and successfully fabricated, which exhibited high photocatalytic activity under 980 nm irradiation. The present report highlights the potential of ET tuning between RE ions and semiconductors toward high performance of NIR photocatalysis. 相似文献
13.
Yujian Wu Xiaoqi Zhao Zhiyu Zhang Jinmeng Xiang Hao Suo Chongfeng Guo 《Ceramics International》2021,47(11):15067-15072
Fluorescent materials have been widely used for anti-counterfeiting of important documents and currencies, wherein their anti-counterfeit abilities could be improved through multi-mode excitation. Herein, dual-mode-excited double-colour-emitting Er3+doped SrBi4Ti4O15 up-conversion (UC) phosphors (SBTO: Er3+) were synthesised, and their UC spectra included green (2H11/2/4S3/2 → 4I15/2) and red (4F9/2 → 4I15/2) emissions from Er3+ ions under 980 or 1550 nm excitation. However, the green emission colour of phosphors was independent of dopant concentration under 980 nm laser irradiation; whereas the final emission colour was dominated by red emission and significantly affected by contents of Er3+ under 1550 nm excitation. These observations demonstrated potential application in dual-mode double-colour anti-counterfeiting. The possible UC mechanisms and emission characteristics of the phosphors using different 980 and 1550 nm irradiation source were contrastively investigated, and some fluorescent security patterns were also designed to demonstrate the potential applications in anti-counterfeiting and concealing important information. 相似文献
14.
Zhicong Sun Tianliang Zhou Ronghui Liu Xueyuan Tang Rong-Jun Xie 《Journal of the American Ceramic Society》2023,106(6):3446-3454
Near-infrared phosphor-converted light-emitting diodes (NIR-pc-LEDs) are superior to traditional NIR-LEDs in spectral modulation, volume, and cost, and their optoelectronic properties are dominantly controlled by the NIR phosphors, which thus boosts the search for high efficiency and broadband NIR phosphors. In this work, we attempt to realize ultra-broadband NIR phosphors by doping Cr3+ in self-emitting SrHfO3 with a weak crystal field. Dual emission bands centered at 770 (host) and 1000 nm (Cr3+) are observed, leading to a wide spectral range of 700–1400 nm. The Cr3+ ions enter the HfO6 octahedron and thus produce an NIR emission with a full width at half maximum of 190 nm and an internal quantum efficiency of 24% under 460 nm excitation. A prototype NIR-pc-LED surface light is demonstrated for machine vision by using NIR-pc-LEDs that combine the blue LED with SrHfO3:Cr. The work paves an avenue for designing super-broadband NIR phosphors by doping Cr3+ or other ions into hosts with self-trapped exciton emission (e.g., halide perovskites). 相似文献
15.
Zhong Jiang Hao Cheng Fengqin Lai Zongliang Xiao Jiangmin Chen Jing Sun Weixiong You 《Journal of the American Ceramic Society》2022,105(7):4731-4743
The doping of transition metal ions in the up-conversion (UC) luminescent material doped with Yb3+/Ln3+ is a facile way to increase their UC luminescence intensities and alter their colors. In this study, La2MgTiO6:Yb3+/Mn4+/Ln3+ (Ln3+ = Er3+, Ho3+, and Tm3+) phosphors showing excellent luminescence properties were prepared by a solid-state method. The sensitivity of the La2MgTiO6:Yb3+/Ln3+/Mn4+ phosphor was double that without Mn4+, because Mn4+ affects the UC emissions of Ln3+ via energy transfer between these ions. Moreover, Mn4+ also acts as a down-conversion activator, which can combine with UC ions to achieve multi-mode luminescence at different wavelengths. Under 980 nm excitation, these samples emit green light (from Er3+ and Ho3+) and blue light (from Tm3+). In contrast, under 365 nm excitation, they emit red light (from Mn4+). Further testing revealed that the La2MgTiO6:Yb3+/Mn4+/Ln3+ phosphors have potential applications in temperature sensing and anti-counterfeiting. 相似文献
16.
17.
Photo/cathodoluminescence and stability of Gd2O2S:Tb,Pr green phosphor hexagons calcined from layered hydroxide sulfate
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Xuejiao Wang Xiaojun Wang Zhihao Wang Qi Zhu Ge Zhu Chuang Wang Shuangyu Xin Ji‐Guang Li 《Journal of the American Ceramic Society》2018,101(12):5477-5486
Hydrothermal reaction at 150°C and pH = 10 for 24 hours crystallized (Gd,RE)2(OH)4SO4 layered hydroxide sulfate (monoclinic structure; RE = Pr, Tb), from which Gd2O2S:RE (hexagonal structure) green phosphor hexagons were derived via facile dehydration in flowing H2 at 1200°C. Rietveld refinement of the XRD patterns yielded cell dimensions that confirmed the direct crystallization of solid solution. Photoluminescence (PL) study at room temperature found absolute quantum yields of ~25.1% and 28.4%, CIE chromaticity coordinates of (0.145, 0.679) and (0.326, 0.566), and fluorescence lifetimes of ~2.36 μs and 1.21 ms for Pr3+ and Tb3+ under 300 and 275 nm UV excitations, respectively. Temperature‐dependent PL analysis (25‐200°C) indicated that both the Pr3+‐ and Tb3+‐doped phosphors have favorably good thermal stability and retained ~65% and 80% at 100°C and ~41% and 47% at 200°C of their initial emission intensities, respectively. The activation energy for the thermal quenching of PL was determined to be ~0.221 (Pr3+) and 0.314 eV (Tb3+). Cathodoluminescence (CL) found that both the phosphors exhibit increasingly higher emission intensity/brightness at a higher acceleration voltage (up to 7 kV) or beam current (up to 50 μA) and are stable under electron bombardment in the studied range. Raising beam current was suggested to be more effective to enhance CL. 相似文献
18.
Deep‐red photoluminescence and long persistent luminescence in double perovstkite‐type La2MgGeO6:Mn4+
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Xiaowen Zhang Jianmin Nie Shanshan Liu Yang Li Jianrong Qiu 《Journal of the American Ceramic Society》2018,101(4):1576-1584
A novel non‐rare‐earth doped phosphor La2MgGeO6:Mn4+ (LMG:Mn4+) with near‐infrared (NIR) long persistent luminescence (LPL) was successfully synthesized by solid‐state reaction. The phosphors can be effectively excited using ultraviolet light, followed by a sharp deep‐red emission peaking at 708 nm, which is originated from 2Eg → 4A2g transition of Mn4+ ions. The luminescent performance was analyzed by photoluminescence (PL) and photoluminescence excitation (PLE) spectra. The crystal field parameters were calculated to describe the environment of Mn4+ in LMG host. The LPL behaviors as well as the mechanisms were systematically discussed. This study suggests that the phosphors will broaden new horizons in designing and fabricating novel NIR long phosphorescent materials. 相似文献
19.
Tianyao Liu Hao Cai Ning Mao Zhen Song Quanlin Liu 《Journal of the American Ceramic Society》2021,104(9):4577-4584
Broadband near-infrared phosphors are essential to realize nondestructive analysis in food industry and biomedical areas. Efficient long-wavelength (>830 nm) phosphors are strongly desired for practical applications. Herein, we demonstrate an efficient broadband NIR phosphor LiInGe2O6:Cr3+, which exhibits a broad NIR emission peaking at ~880 nm with a full width at half maximum of 172 nm upon 460 nm excitation. The internal/external quantum efficiencies of LiInGe2O6:Cr3+ are measured to be 81.2% and 39.8%, respectively. The absorption of the phosphor matches well with commercial blue LEDs. Using the fabricated phosphor converted LED illuminating human palm, distribution of blood vessels can be clearly recognized under a NIR camera. These results indicate that LiInGe2O6:Cr3+ is a promising candidate to be used in future non-destructive biological applications. 相似文献
20.
Vanadate based down conversion phosphors have been synthesized by a novel co-precipitation technique. The effect of pH on crystal structure, particle size, morphology and luminescence properties were investigated by XRD, SEM-EDAX, FT-IR and PL measurements. As different from other reports (blue, green emission) the produced phosphors have shown greenish–yellow emission, owing to their fine particle size. A broad band excitation (280–370 nm), ascribed to 1S0→3P1 and an intense greenish–yellow band emission (410–700 nm) attributed to 3P1→1S0 transition of Bi3+ were observed. A strong greenish–yellow emission was measured with 3 mol. % of Bi3+ ions, as an optimum dopant concentration. The characteristic NIR emission of Yb3+, owing to 2F5/2→2F7/2 was recorded at 1039 nm, as a result of efficient energy transfer from Bi3+ to Yb3+, ions. The phosphors with chemical composition as Y0.96VO4: Bi0.033+, Yb0.013+ and Y0.87VO4: Bi0.033+,Yb0.13+ are suggested to be the novel candidates for the efficient down conversion of broad band ultra violet (UV) light into visible/near infrared (NIR) emission, as DC layers on c-Si solar cells for better harvesting the solar spectrum via spectral matching phenomena. 相似文献