机构地区:[1]吉林化工学院化学与制药工程学院,吉林132022 [2]吉林化工学院分析测试中心,吉林132022
出 处:《复合材料学报》2024年第7期3587-3597,共11页Acta Materiae Compositae Sinica
基 金:国家自然科学基金(51902125);吉林省科技发展计划(YDZJ202101ZYTS029);吉林市科技发展计划(20210103092);第七批吉林省青年科技人才托举工程(QT202316)。
摘 要:为了获得具有红光发射的上转换纳米材料,以实现深层生物成像的应用,采用热分解法制备了一系列Tm^(3+)、Ho^(3+)掺杂NaErF_(4)@NaYF_(4)核壳上转换纳米晶,并对其形貌、结构和发光性能进行了表征。结果表明:所制备NaErF_(4)、NaErF_(4)∶Tm^(3+)和NaErF_(4)∶Ho^(3+)裸核均为六方相结构,呈现良好的球形形貌,平均粒径分别为28.01 nm、23.19 nm、27.89 nm。包覆NaYF_(4)惰性壳层后,样品晶型没有改变,形貌变为短棒状,平均长度增大至37.82 nm、38.51 nm、42.65 nm。在980 nm近红外光激发下,由于Er^(3+)的^(4)F_(9/2)→^(4)I_(15/2)跃迁,所制备NaErF_(4)、NaErF_(4)∶Tm^(3+)和NaErF_(4)∶Ho^(3+)裸核均呈现明显的红光发射,且包覆NaYF_(4)惰性壳层后,发光强度和荧光寿命都明显增加,特别是NaErF_(4)@NaYF_(4)核壳样品的发光强度约是NaErF_(4)裸核的1787倍,荧光寿命达到2.04 ms。此外,与NaErF_(4)@NaYF_(4)纳米棒相比,NaErF_(4)∶(Tm^(3+),Ho^(3+))@NaYF_(4)体系中的Tm^(3+)、Ho^(3+)充当了能量捕获中心且与Er^(3+)之间发生能量传递,使其具有更大的红绿发射峰比值(R/G),发光颜色更趋近于红色,与色坐标(CIE)颜色区域相一致。最后,根据发光强度与激发功率的关系,详细分析了上转换纳米晶的发光增强机制及可能存在的能量传递过程。In order to obtain upconversion nanomaterials with bright red emission for deep bioimaging applications,a series of Tm^(3+),Ho^(3+)doped NaErF_(4)@NaYF_(4) core-shell upconversion nanocrystals were prepared by thermal decomposition method,and their morphology,structure and luminescence properties were characterized.The results show that NaErF_(4),NaErF_(4)∶Tm^(3+)and NaErF_(4)∶Ho^(3+)bare core all exhibit hexagonal phase structure and good spherical morphology,with average sizes of 28.01 nm 23.19 nm,and 27.89 nm,respectively.After coating NaYF_(4) inert shell,the crystal phase remains unchanged,but the morphology became short rod-like,and the average length increases to 37.82 nm,38.51 nm,42.65 nm.Under the excitation of 980 nm near-infrared light,NaErF_(4),NaErF_(4)∶Tm^(3+)and NaErF_(4)∶Ho^(3+)show obvious red emission due to the ^(4)F_(9/2)→^(4)I_(15/2) transition of Er^(3+),and the luminescence intensity and lifetime increase significantly after coating NaYF_(4) inert shell.In particular,the luminescence intensity of NaErF_(4)@NaYF_(4) core-shell sample is about 1787 times that of NaErF_(4) bare core,and the lifetime is 2.04 ms.In addition,compared with NaErF_(4)@NaYF_(4),the Tm^(3+),Ho^(3+)ions in the NaErF_(4)∶(Tm^(3+),Ho^(3+))@NaYF_(4) system act as energy trapping centers and generate energy transfer with Er^(3+),resulting in a larger red-green emission peak ratio(R/G),and the luminescence color is closer to red,which is consistent with the chromaticity coordinate(CIE)color region.Finally,according to the relationship between luminescence intensity and excitation power,the upconversion luminescence enhanced mechanism and the possible energy transfer process are analyzed in detail.
关 键 词:上转换发光 NaErF_(4)纳米晶 红光发射 核壳 掺杂
分 类 号:O734[理学—晶体学] TB332[一般工业技术—材料科学与工程]
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...
正在载入数据...