近红外二区长波发射Na_(3)YSi_(3)O_(9):x Cr^(3+)硅酸盐及多格位占据光谱展宽  

Long wavelength near-infrared II emitting Na_(3)YSi_(3)O_(9):x Cr^(3+)silicate and spectral broadening by multi-site occupancy

作　　者：龚长帅 王建通 王渤文 薛绪岩 王雪娇 Gong Chang-Shuai;Wang Jian-Tong;Wang Bo-Wen;Xue Xu-Yan;Wang Xue-Jiao(School of Chemistry and Materials Engineering,Bohai University,Jinzhou 121013,China)

机构地区：[1]渤海大学化学与材料工程学院,锦州121013

出　　处：《物理学报》2024年第15期208-217,共10页Acta Physica Sinica

基　　金：辽宁省教育厅自然科学基金(批准号:JYTMS20231627);辽宁省科技厅自然科学基金(批准号:2020-MS-286)资助的课题

摘　　要：以Cr^(3+)为激活剂的荧光粉被认为是目前最有可能实现商业化的近红外材料.但目前这类荧光粉的发射波长一般位于小于850 nm的近红外一区,以Cr^(3+)为激活剂实现近红外二区发射仍然具有挑战.本文采用普适的固相法制备了一系列Na_(3)Y_(1–x)Si_(3)O_(9):x Cr^(3+)硅酸盐荧光粉,利用Na_(3)YSi_(3)O_(9)硅酸盐属性及结构中多种适于Cr^(3+)占据的八面体位点有效红移并展宽光谱.对样品的物相、晶体结构、微观形貌、光致发光、主发射峰衰减和热稳定性等进行了系统研究.结果显示,所制样品均为纯相,形貌不均匀略有团聚,尺寸在微米量级.Cr^(3+)在Na_(3)YSi_(3)O_(9)晶格中位于弱晶体场环境,八面体晶体场参数Dq和Racah参数B的比值Dq/B=2.29.在485 nm蓝光激发下Na3Y_(1–x)Si_(3)O_(9):x Cr^(3+)荧光粉最强发射峰位于984 nm处(NIR II区),长于大多数Cr^(3+)激活的荧光粉.且得益于Cr^(3+)在晶格中的多格位占据,发射光谱的半峰宽高达183 nm.Na3Y_(1–x)Si_(3)O_(9):x Cr^(3+)中最佳掺杂浓度为3%,猝灭机理为Cr^(3+)离子间的偶极-偶极作用.Na3Y_(1–x)Si_(3)O_(9):x Cr^(3+)主发射峰荧光衰减动力学分析表明室温荧光寿命约为37.95μs,且随着掺杂浓度增大及温度升高(至423 K)逐渐降低.Phosphors-converted near-infrared LED(pc-NIR LED)possesses applications in various fields including food quality analysis,night vision,biomedical imaging,and biomedicine.The design and development of broadband near-infrared(NIR)phosphors with the required properties are of decisive significance for pc-NIR LED devices.The Cr^(3+)doped phosphors are considered to be most promising near-infrared materials for commercialization.Broadband NIR luminescent materials doped with Cr^(3+)have attracted more and more attention due to their potential applications in NIR light sources.However,the emission wavelength of Cr^(3+)doped phosphor is generally located in the NIR I region of less than 850 nm,and realizing the NIR II region emission is still a challenge.In this work,a series of Cr^(3+)doped Na_(3)YSi_(3)O_(9) new silicate phosphors is prepared by solid-state method in N_(2 )atmosphere at 1150℃for 8 h.We take advantages of the silicate nature and the multi octahedral sites suitable for Cr^(3+)in the studied Na_(3)YSi_(3)O_(9) materials to redshift and broaden the spectrum.The phase,crystal structure,microstructure,photoluminescence,main emission peak decay and thermal stability of the samples are systematically studied.The results show that the prepared samples are pure phases,with uneven morphology,slight agglomeration,and the sizes in the micrometer range.The Cr^(3+)is located in the weak crystal field environment of Na_(3)YSi_(3)O_(9) lattice,with a Dq/B value of 2.29.Under the excitation of blue light at a wavelength of 485 nm,the strongest emission peaks ofNa_(3)Y_(1–x)Si_(3)O_(9):x Cr^(3+)phosphors are located at 984 nm(NIR II region),which is longer than those of most Cr^(3+)activated phosphors.Due to the multi-site occupation of Cr^(3+)in the lattice,the full width at half maximum(FWHM)of the emission spectrum is as high as 183 nm.The optimal doping concentration ofNa_(3)Y_(1–x)Si_(3)O_(9):x Cr^(3+)is 3%,and the quenching mechanism is the dipole-dipole interaction between Cr^(3+)ions.Fluorescence decay cur

关 键 词：硅酸盐 Cr^(3+) 宽带近红外 多格位 

分 类 号：TQ422[化学工程]