Enhancement Effect of K+ Doping on Luminescence Properties of Na2CaSiO4∶Tb3+ Phosphor

doi:10.16553/j.cnki.issn1000-985x.2026.0061

Abstract

Abstract: In this paper， Na₂Ca_1-_x SiO₄∶xTb³⁺（x=0~0.08） and Na₂Ca_0.95SiO₄∶0.05Tb³⁺/yK⁺（y=0.03~0.07） series of green phosphors were synthesized via the high-temperature solid-state reaction method. The effects of Tb³⁺ single doping and Tb³⁺/K⁺ co-doping on the phase structure， micro-morphology， optical absorption， luminescence properties， chromaticity coordinates， and thermal stability of the samples were systematically investigated. The results demonstrate that doping does not alter the cubic crystal phase structure of the Na₂CaSiO₄ matrix， which exhibit high crystallinity. Tb³⁺ effectively occupy Ca²⁺ lattice sites and reduce the band gap of the matrix. The micro-morphology of the samples is irregular with evident agglomeration. Under excitation at 376 nm， the Na₂Ca_1-_x SiO₄∶xTb³⁺ phosphor exhibits the strongest characteristic emission of Tb³⁺ corresponding to the ⁵D₄→⁷F₅ transition at 544 nm， and the optimal doping molar concentration is x=0.05. For the Na₂Ca_0.95SiO₄∶0.05Tb³⁺/yK⁺ （y=0.03~0.07） phosphors， the optimal doping molar concentration of K⁺ is y=0.05. The luminescent intensity of the optimized composition Na₂Ca_0.95SiO₄∶0.05Tb³⁺/0.05K⁺ is approximately 2.3 times that of Na₂Ca_0.95SiO₄∶0.05Tb³⁺. It possesses a fluorescence lifetime of 3.006 ms， a band gap of 5.03 eV， and CIE chromaticity coordinates of （0.255， 0.551）. At 473 K， its luminescent intensity still maintains 92.4% of that at room temperature （298 K）， indicating excellent thermal stability. This phosphor is a promising green-emitting material with potential applications in white light-emitting diodes （W-LEDs）.

Key words: Na₂CaSiO₄∶Tb³⁺; high temperature solid state method; green phosphor; K⁺ doping; luminescence property

CLC Number:

TQ422

MENG Xiaoyan, ZHENG Shuyi, LUO Chaoming, TANG Wenjie, WU Lidan, YANG Liusai. Enhancement Effect of K⁺ Doping on Luminescence Properties of Na₂CaSiO₄∶Tb³⁺ Phosphor[J]. Journal of Synthetic Crystals, 2026, 55(9): 1460-1471.

Figures/Tables 13

Fig.1 XRD patterns of NCSO∶xTb3+（x=0~0.08）（a） and NCSO∶0.05Tb3+/yK+（y=0.03~0.07）（b）， the crystal structure of Na2CaSiO4 （c）， and XRD refinement pattern of Na2Ca0.95SiO4∶0.05Tb3+ （d）

Table 1 Lattice parameters， crystallite sizes （D）， band gap（Eg）， CIE coordinates and lifetime （ τ ） of Na2Ca1-x SiO4∶xTb3+ and Na2Ca0.95Tb0.05SiO4∶0.05Tb3+/yK+

Sample	a=b=c/nm	V/nm³	D/nm	R_wp/%	χ²	E_g	CIE （X， Y）	τ/ms
x=0 x=0.01	0.748 95 0.748 70	0.420 11 0.419 69	37.9 37.5	14.895 13.962	1.753 1.419	5.84	—	—
x=0 x=0.01	0.748 95 0.748 70	0.420 11 0.419 69	37.9 37.5	14.895 13.962	1.753 1.419	5.01	（0.213， 0.362）	3.109
x=0.03	0.748 49	0.419 33	36.6	14.028	1.445	5.02	（0.232， 0.452）	3.047
x=0.04	0.748 36	0.419 11	36.8	14.282	1.621	5.01	（0.238， 0.479）	2.972
x=0.05	0.748 30	0.419 01	34.8	12.893	1.239	5.01	（0.238， 0.487）	2.954
x=0.06	0.747 72	0.418 04	37.1	14.138	1.482	5.01	（0.239， 0.486）	2.872
x=0.07	0.748 13	0.418 73	37.0	13.433	1.387	5.00	（0.241， 0.494）	2.831
x=0.08	0.748 50	0.419 35	37.2	13.090	1.255	5.02	（0.241， 0.488）	2.811
y=0.03	0.749 25	0.420 61	36.4	13.051	1.297	5.02	（0.245， 0.504）	2.931
y=0.04	0.748 86	0.419 95	37.0	13.531	1.444	5.02	（0.253， 0.541）	2.993
y=0.05	0.748 59	0.419 50	38.2	13.602	1.374	5.03	（0.255， 0.551）	3.006
y=0.06	0.748 98	0.420 16	38.7	13.088	1.329	5.00	（0.255， 0.547）	2.990
y=0.07	0.749 18	0.420 49	39.5	13.307	1.387	5.02	（0.254， 0.545）	3.010

Fig.2 SEM image （a） and EDS （b） of Na2Ca0.95SiO4∶0.05Tb3+， and SEM image （c） and EDS （d） of Na2Ca0.95SiO4∶0.05Tb3+/0.05K+

Fig.3 FT-IR spectra of Na2CaSiO4 （a）， Na2Ca0.95SiO4∶0.05Tb3+ （b） and Na2Ca0.95SiO4∶0.05Tb3+/0.05K+ （c）

Fig.4 UV-Vis diffuse reflectance spectra （a） and the energy dependence of （αhν）2 （b） of NCSO， NCSO∶0.05Tb3+， and NCSO∶0.05Tb3+/0.05K+

Fig.5 Excitation spectra of NCSO∶0.05Tb3+ and NCSO∶0.05Tb3+ /0.05K+

Fig.6 Emission spectra of Na2Ca1-x SiO4∶xTb3+ （inset： variation of integrated emission intensity with Tb3+ concentration）

Fig.7 Curves of lg（I/x） versus lg x for Na2Ca1-x SiO4∶xTb3+ at λem=488 nm and λem=544 nm

Fig.8 Emission spectra of NCSO∶0.05Tb3+/yK+（y= 0，0.03~0.07）（a）， and variation of integrated emission intensity with K+ concentration （b）

Fig.9 Fluorescence decay curves of NCSO∶0.05Tb3+ （a） and NCSO∶0.05Tb3+/0.05K+ （b）

Fig.10 CIE chromaticity diagram of NCSO∶0.05Tb3+ and NCSO∶0.05Tb3+/yK+ （y=0.03~0.05）

Fig.11 Variations of the relative emission intensity as a function of temperature （a） and plot of ln（I0/I-1） versus 1/（kBT）（b） for Na2Ca0.95SiO4∶0.05Tb3+/0.05K+

Fig.12 Electroluminescence spectrum and photographs of the fabricated white LED device at a current of 200 mA （a）， EL spectra （b）， the parameters LE， CRI， and CCT （c）， and CIE chromaticity diagram （d） at various currents

References 27

[1]	卓芳平，张　伟，火军明，等. Na₂CaSiO₄∶RE³⁺（RE=Ce³⁺， Tb³⁺， Eu³⁺）的制备及发光特性［J］. 发光学报， 2012， 33（3）： 238-242.
	ZHUO F P， ZHANG W， HUO J M， et al. Synthesize and luminescence properties of Na₂CaSiO₄∶RE³⁺（RE=Ce³⁺， Tb³⁺， Eu³⁺）［J］. Chinese Journal of Luminescence， 2012， 33（3）： 238-242 （in Chinese）. DOI URL
[2]	刘　杨，李锦洋，岳浩东，等. 近紫外激发颜色可调的Ca₃Nb_1.6875Ga_3.1875O₁₂∶Dy³⁺/Tm³⁺荧光粉制备及其性能研究［J］. 中国稀土学报， 2025， 43（1）： 57-68.
	LIU Y， LI J Y， YUE H D， et al. Preparation and luminescent properties of near-ultraviolet excited color tunable Ca₃Nb_1.6875Ga_3.1875O₁₂∶Dy³⁺/Tm³⁺ phosphors［J］. Journal of the Chinese Society of Rare Earths， 2025， 43（1）： 57-68 （in Chinese）.
[3]	陈江敏，赖凤琴，康立强，等. 溶胶-凝胶法制备Gd₂Zr₂O₇∶Eu³⁺红色荧光粉及其发光性能研究［J］. 中国稀土学报， 2024， 42（4）： 666-674.
	CHEN J M， LAI F Q， KANG L Q， et al. Preparation and luminescence properties of Gd₂Zr₂O₇∶Eu³⁺ red phosphor via sol-gel method［J］. Journal of the Chinese Society of Rare Earths， 2024， 42（4）： 666-674 （in Chinese）.
[4]	张朝光. 硅酸盐基纳米材料的制备及白光特性研究［J］. 功能材料， 2023， 54（11）： 11147-11151. DOI
	ZHANG C G. Preparation and white light properties of silicate basednanomaterials［J］. Journal of Functional Materials， 2023， 54（11）： 11147-11151 （in Chinese）. DOI
[5]	欧奕意，王笑军，梁宏斌. K₃La（PO₄）₂基质中Tb³⁺的发光和能量传递［J］. 发光学报， 2022， 43（9）： 1350-1360.
	OU Y Y， WANG X J， LIANG H B. Luminescence and energy transfer of Tb³⁺ in K₃La（PO₄）₂ ［J］. Chinese Journal of Luminescence， 2022， 43（9）： 1350-1360 （in Chinese）. DOI URL
[6]	苏小娜，万　英，周芷萱，等. Na₂CaSiO₄∶Sm³⁺， Eu³⁺荧光粉的发光特性和能量传递［J］. 物理学报， 2017， 66（23）： 230701.
	SU X N， WAN Y， ZHOU Z X， et al. Luminescence properties and energy transfer of Na₂CaSiO₄∶Sm³⁺， Eu³⁺phosphor［J］. Acta Physica Sinica， 2017， 66（23）： 230701 （in Chinese）. DOI URL
[7]	HE J， YAN C， HUANG M M， et al. Mechanistic insight into energy-transfer dynamics and color tunability of Na₄CaSi₃O₉∶Tb³⁺， Eu³⁺ for warm white LEDs［J］. Chemistry-A European Journal， 2020， 26（25）： 5619-5628. DOI URL
[8]	DEEPALI， JAYASIMHADRI M. UV-excited blue- to green-emitting Tb³⁺-activated sodium calcium metasilicate colour tunable phosphor for luminescence devices［J］. Luminescence， 2022， 37（9）： 1465-1474. DOI URL
[9]	SHIVAKUMARA J， MANJUNATHA C， HARI KRISHNA R， et al. Enhancement of photoluminescence of Cd_0.95Eu_0.05SiO₃ phosphor using Na⁺ and K⁺ as charge compensators［J］. Chemical Physics， 2021， 551： 111319. DOI URL
[10]	GAO X， ZHANG W T， WANG X M， et al. Charge compensation effects of alkali metal ions M⁺ （Li⁺， Na⁺， K⁺） on luminescence enhancement in red-emitting Ca₃Si₂O₇∶Eu³⁺ phosphors［J］. Journal of Alloys and Compounds， 2022， 893： 162265. DOI URL
[11]	XIONG H R， GAO X， YUAN F， et al. Photoluminescence enhancement of orange-emitting Ca₅（PO₄）₂SiO₄∶Sm³⁺ phosphor through charge compensation of A⁺ （Li⁺， Na⁺ and K⁺） ions for white light-emitting diodes［J］. Dalton Transactions， 2022， 51（22）： 8874-8884. DOI URL
[12]	DENG J M， WANG Z H， ZHOU W P， et al. Enhancement of luminescence properties of Ca₂Al₂SiO₇∶Eu³⁺ red phosphors by Li⁺， Na⁺， K⁺， Mg²⁺ charge compensators［J］. Ceramics International， 2023， 49（23）： 39568-39575. DOI URL
[13]	SUN J， ZHANG B， ZHU W， et al. Enhancement of luminescence and thermal stability of NaLi₃SiO₄∶Eu phosphor by co-doping K⁺ ions［J］. Journal of Solid State Chemistry， 2024， 329： 124437. DOI URL
[14]	TANG H， CHEN M， ZHANG X Y， et al. Effect of charge compensators （Li⁺， Na⁺， K⁺， Rb⁺， Cs⁺） on the luminescence properties of Na₄CaSi₃O₉∶Eu³⁺ red phosphor［J］. Materials Research Bulletin， 2025， 184： 113255. DOI URL
[15]	HUANG X， ZHANG W T， WANG X M， et al. Optical characteristics and energy transfer between Eu³⁺ and Dy³⁺ in Na₂CaSiO₄∶Dy³⁺， Eu³⁺ white-emitting phosphor［J］. Journal of Alloys and Compounds， 2021， 873： 159803. DOI URL
[16]	KAUR H， JAYASIMHADRI M， SAHU M K， et al. Synthesis of orange emitting Sm³⁺ doped sodium calcium silicate phosphor by sol-gel method for photonic device applications［J］. Ceramics International， 2020， 46（16）： 26434-26439. DOI URL
[17]	杨流赛，孟晓燕，罗　伟，等. CaMoO₄∶Eu³⁺纳米荧光粉的尺寸调控及光学性能研究［J］. 材料科学与工艺， 2019， 27（4）： 42-49.
	YANG L S， MENG X Y， LUO W， et al. Size control and optical properties of CaMoO₄∶Eu³⁺ nanophosphors［J］. Materials Science and Technology， 2019， 27（4）： 42-49 （in Chinese）.
[18]	GIRSOVA M A， GOLOVINA G F， ANFIMOVA I N， et al. Infrared spectroscopy study of silver-containing composite materials based on nanoporous silicate glass doped with Tb³⁺ or Sm³⁺ ions［J］. Glass Physics and Chemistry， 2019， 45（5）： 325-331. DOI
[19]	KAUR H， TIKU V， PRASAD A， et al. Luminescent and colorimetric properties of the sol-gel derived mono-phase Dy³⁺ doped silicate-based phosphor for w-LED applications［J］. Journal of Sol-Gel Science and Technology， 2022， 101（2）： 443-452. DOI
[20]	ZHAN J W， PENG S Y， ZHU Y X， et al. Phase transitions and optical properties of Tb³⁺ activated NaY（WO₄）₂ phosphors［J］. Ceramics International， 2024， 50（3）： 4896-4906. DOI URL
[21]	MIAO S， HU J， GAO M， et al. Tunable blue-green-emitting Na₄CaSi₃O₉∶Ce³⁺， Li⁺， Tb³⁺ phosphor with energy transfer for near-UV white LEDs［J］. Materials Today Sustainability， 2020， 9： 100036. DOI URL
[22]	WANG Q Q， WU J X， WU B L， et al. Morphology regulation， small-size effect and fluorescence and magnetic properties of GdPO₄·H₂O∶Tb³⁺ ［J］. Materials Research Bulletin， 2024， 170： 112565. DOI URL
[23]	BLASSE G. Energy transfer in oxidic phosphors［J］. Physics Letters A， 1968， 28（6）： 444-445. DOI URL
[24]	王元娥，王　晶，葛彩霞，等. Tb³⁺， Sm³⁺掺杂的可变色KSrGd（WO₄）₃荧光粉的制备及发光性能研究［J］. 人工晶体学报， 2025， 54（4）： 674-683.
	WANG Y E， WANG J， GE C X， et al. Synthesis and luminescence properties of Tb³⁺， Sm³⁺ doped color-tunable KSrGd（WO₄）₃ phosphors［J］. Journal of Synthetic Crystals， 2025， 54（4）： 674-683 （in Chinese）.
[25]	DEXTER D L. A theory of sensitized luminescence in solids［J］. The Journal of Chemical Physics， 1953， 21（5）： 836-850. DOI URL
[26]	LAIDLER K J. The development of the Arrhenius equation［J］. Journal of Chemical Education， 1984， 61（6）： 494. DOI URL
[27]	SUN L L， DEVAKUMAR B， LIANG J， et al. Highly efficient Ce³⁺→Tb³⁺ energy transfer induced bright narrowband green emissions from garnet-type Ca₂YZr₂（AlO₄）₃∶Ce³⁺， Tb³⁺ phosphors for white LEDs with high color rendering index［J］. Journal of Materials Chemistry C， 2019， 7（34）： 10471-10480. DOI URL

Enhancement Effect of K⁺ Doping on Luminescence Properties of Na₂CaSiO₄∶Tb³⁺ Phosphor

RichHTML

PDF (PC)

Knowledge

Abstract

Cite this article

share this article

Figures/Tables 13

References 27

Related Articles 15

Recommended Articles

Metrics

Comments

[1]	WANG Haohan, WEI Qinhua, SHU Chang, YIN Hang, TANG Gao, ZHANG Suyin, QIN Laishun. Growth and Luminescence Properties of Sm²⁺-Ce³⁺ Co-Doped CLLB Scintillation Crystals [J]. Journal of Synthetic Crystals, 2026, 55(2): 201-210.
[2]	HUANG Qu, JIANG Hongxi, ZHOU Bo. Luminescent Properties of CaLa₂(WO₄)₄∶Eu³⁺,Sm³⁺ as Novel Red Phosphor for White LEDs [J]. JOURNAL OF SYNTHETIC CRYSTALS, 2025, 54(1): 69-76.
[3]	LIU Yunyun, HUANG Chuanxin, WANG Meng, WANG Yan. Synthesis and Luminescence Properties of Dy³⁺/Eu³⁺ Co-Doped CaLaGa₃O₇ Color Tunable Phosphors [J]. JOURNAL OF SYNTHETIC CRYSTALS, 2024, 53(9): 1560-1567.
[4]	AN Hangyi, HUANG Yanxi, WANG Airong, WANG Xiaoli, LI Jiaming, SHI Zhongfeng. A Novel Three-Dimensional Ni (II) Complex: Synthesis, Crystal Structure and Detection for Fe³⁺, CrO^2-₄ and Cr₂O^2-₇ in Water [J]. JOURNAL OF SYNTHETIC CRYSTALS, 2024, 53(9): 1599-1607.
[5]	HU Zhengkai, YANG Weibin, XIONG Feibing, GUO Yisheng, BAI Xin, LI Mingming. Preparation and Luminescence Properties of Sm³⁺ Doped Na₅Y_1-x(MoO₄)_4-y(WO₄)_y Phosphors with High Thermal Stability [J]. JOURNAL OF SYNTHETIC CRYSTALS, 2024, 53(6): 1016-1025.
[6]	MENG Xiaoyan, LIAO Yun, ZHANG Lirong, ZHANG Yumeng, WU Lidan, YANG Liusai. Preparation and Luminescent Properties of GdPO₄∶Tb³⁺ Phosphors [J]. JOURNAL OF SYNTHETIC CRYSTALS, 2024, 53(1): 107-114.
[7]	WANG Wudi, WANG Qingguo, XUE Yanyan, TANG Huili, XU Zihan, ZHANG Chenbo, FANG Qiancheng, WU Feng, LUO Ping, XU Xiaodong, SU Liangbi, LI Yan, HAN Jianfeng, LU Zhanwen, XU Jun. Growth and Luminescence Properties of Pr³⁺ Doped Alkaline Earth Mixed Fluoride Laser Crystals [J]. JOURNAL OF SYNTHETIC CRYSTALS, 2023, 52(7): 1258-1269.
[8]	YIN Zilong, FENG Guangwen, CHEN Henglei. Effect of Different Synthesis Methods on the Luminescence Properties of LiMgPO₄∶Dy [J]. JOURNAL OF SYNTHETIC CRYSTALS, 2023, 52(2): 315-321.
[9]	LU Qin, FANG Chuanli, WANG You, WU Dongni, WANG Yujie, LOU Chenglong. Preparation and Luminescence Properties of LaNbO₄∶Dy³⁺, Ca²⁺ Phosphors [J]. JOURNAL OF SYNTHETIC CRYSTALS, 2023, 52(10): 1816-1821.
[10]	CUI Ruirui, CHEN Qian, ZHANG Xin, DENG Chaoyong. Preparation and Property of Ba₃Bi₂(PO₄)₄∶Tb³⁺ Phosphors [J]. JOURNAL OF SYNTHETIC CRYSTALS, 2022, 51(6): 1069-1075.
[11]	LI Haolai, YANG Weibin, LIN Yizhan, LING Shuang, XIONG Feibing. Preparation and Luminescent Properties of Sr₇Sb₂O₁₂∶Dy³⁺ Phosphors [J]. JOURNAL OF SYNTHETIC CRYSTALS, 2022, 51(11): 1921-1928.
[12]	WANG Yuhuan, CHEN Yongjie, ZHANG Wenhua, GENG Xiujuan, YANG Ying. Synthesized and Luminescent Properties of Li(Na, K)Ba(Sr, Ca)B₉O₁₅∶Eu³⁺ Phosphor [J]. JOURNAL OF SYNTHETIC CRYSTALS, 2021, 50(9): 1694-1701.
[13]	WANG Qingguo, LIU Bo, LUO Ping, TANG Huili, WU Feng, KANG Sen, DUAN Jinzhu, WANG Qinfeng, XU Jun. Crystal Growth and Scintillation Luminescence Properties of Ti:Al₂O₃ Crystals Grown with Kyropoulos Method [J]. JOURNAL OF SYNTHETIC CRYSTALS, 2021, 50(4): 762-767.
[14]	TANG Wanjuan, GUO Qingfeng, SU Ke, MEI Lefu, LIAO Libing. Synthesis, Structure and Photoluminescent Properties of Ca_1.8Li_0.6La_0.6-x(PO₄)₂∶xEu³⁺Phosphor with Whitlockite Structure [J]. JOURNAL OF SYNTHETIC CRYSTALS, 2021, 50(11): 2081-2085.
[15]	HE Nuotian;TANG Huili;LIU Bo;ZHANG Hao;ZHU Zhichao;ZHAO Hengyu;XU Jun. Study on the Luminescence Properties of Ge-doped β-Ga2O3 Crystals [J]. JOURNAL OF SYNTHETIC CRYSTALS, 2020, 49(8): 1534-1540.