摘要
力致发光材料具有将机械刺激转变为光子发射的独特性能,因而被广泛应用于结构健康诊断、信息防伪、生物工程和电子皮肤等力学传感领域。然而,已报道的力致发光材料种类有限,且对于力致发光相关的载流子跃迁过程理解不够深入,极大地限制了其开发和应用。针对上述问题,本工作开发了新型混合阴离子型力致发光材料Ba_(2)Gd(BO_(3))_(2)Cl:Ln(Ln=Eu,Tb,Dy,Sm,Nd),并探究了其光致发光性能与相关载流子跃迁过程。该研究通过X射线粉末衍射、扫描电子显微镜、多模式激发下的稳态和瞬态光谱技术研究了样品的结构形貌、光致发光与力致发光性能,提出了该材料可能的发光机制。研究结果表明,在280 nm光激发下,Ba_(2)Gd-(BO_(3))_(2)Cl:Eu的发射峰位于536,594,613,625,654,695,710 nm,第一个宽峰和其余窄峰分别对应于Eu^(2+)和Eu^(3+)的发射,即掺杂的Eu呈现混合价态。而在机械作用下,Ba_(2)Gd(BO_(3))_(2)Cl:Eu几乎只表现出Eu^(3+)的橙红光发射,这可能是由于机械作用优先激发基质中的价带电子所致。此外,Eu的光致发光和力致发光最佳掺杂浓度均为2%。在0.23~1.55 mJ的冲击能下,力致发光强度与冲击能量呈线性关系。通过改变掺杂镧系元素的种类,实现了力致发光从可见光区域到近红外区域的拓展。这项工作为解释混合价态材料的力致发光机制提供了思路,并在应力传感领域呈现出潜在的应用价值。
Mechanoluminescent(ML)materials show unique energy conversion features from mechanical stimula⁃tion to photon emission,making them widely used in mechanical sensing fields such as structural health diagnosis,information anti-counterfeiting,bioengineering,and electronic skins.However,the species of reported ML materials are rare and the understanding on the ML-related charge carrier transportation is insufficient,which significantly lim⁃its its development and application.In this work,novel mixed-anion typed ML materials namely Ba_(2)Gd(BO_(3))_(2)Cl∶Ln(Ln=Eu,Tb,Dy,Sm,Nd)were developed,and the charge carrier transportation processes involved in photolumi⁃nescence(PL)and ML were examined.The crystal structure,morphology,PL/ML properties and mechanism of the samples were studied by X-ray diffraction,scanning electronic microscopy,and steady-state and transient spectral techniques under multi-mode excitation.The experimental results indicated that the emissions of Ba_(2)Gd(BO_(3))_(2)Cl∶Eu were peaked at 536,594,613,625,654,695,710 nm under 280 nm excitation.The first broad emission and other sharp ones were assigned to Eu^(2+)and Eu^(3+),respectively,showing a mixed valence states of doped Eu ions.Interest⁃ingly,the Ba_(2)Gd(BO_(3))_(2)Cl∶Eu almost exhibited orange emission from Eu^(3+)under mechanical stimulation,which may be attributed to the preferential excitation of valence band electrons in the host under stress.This study also showed that the optimal doping Eu concentrations in Ba_(2)Gd(BO_(3))_(2)Cl for PL and ML were both at 2%,and the mechanolumi⁃nescent intensity was linearly related to the impact energy in the range of 0.23-1.55 mJ.By changing the type of doped lanthanide,we expanded the wavelengths of ML from visible to near infrared region.This work may provide a new way to understand the mechanism of ML in phosphors including mixed valence states and the materials presented in this work show promoting applications in the field of advanced stress sensing.
作者
贺慰
潘鑫
杨汝军
庄逸熙
解荣军
HE Wei;PAN Xin;YANG Rujun;ZHUANG Yixi;XIE Rongjun(College of Materials and Fujian Key Laboratory of Surface and Interface Engineering for High Performance Materials,Xiamen University,Xiamen 361005,China;State Key Laboratory of Physical Chemistry of Solid Surfaces,Xiamen University,Xiamen 361005,China)
出处
《发光学报》
EI
CAS
CSCD
北大核心
2023年第7期1324-1333,共10页
Chinese Journal of Luminescence
基金
国家自然科学基金(52172156,51832005)。
关键词
力致发光
稀土掺杂发光材料
混合阴离子化合物
能量传递
力致发光机理
mechanoluminescence
rare earth doped luminescent materials
mixed-anion compound
energy trans⁃fer
mechanoluminescent mechanism
