共查询到20条相似文献,搜索用时 15 毫秒
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量子点LED采用胶体量子点为LED发光层,通过调节量子点的尺寸可以制作出覆盖可见以及近红外光谱的量子点LED(QD-LED),而且量子点LED器件发出的光谱范围很窄(光谱半高宽可达30 nm).为了研究不同发光颜色的QD-LED器件特性,本文采用具有523 nm和608 nm发光波长的CdSe/ZnS核壳型量子点为发光层、poly-TPD为空穴传输层、ZnO为电子传输层,制备了量子点红光和绿光LED并讨论了器件的相关特性.这些结果对量子点LED在飞机驾驶舱以及医疗器械照明方面的应用提供了参考,但要满足商业化的需求其寿命、亮度以及效率还需要进一步的提高. 相似文献
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水溶性CdHgTe合金量子点的制备与表征 总被引:1,自引:0,他引:1
以巯基乙酸为稳定剂, 在水溶液中加热CdCl2、HgCl2 和 NaHTe的混合物直接合成CdHgTe合金量子点. 分别用荧光光谱、红外光谱、X射线衍射及透射电镜对其光谱性能、表面基团和结构形貌进行了表征. 结果表明, 合金量子点的发射波长在536到688 nm范围内连续可调, 掺杂后量子点的发射光谱变宽, 半高峰宽为70~90 nm; CdHgTe的荧光量子产率介于1.5%到6.7%之间; 巯基与CdHgTe量子点表面的Cd2+离子发生键合, 而使巯基乙酸结合于量子点表面; 合金量子点具有闪锌矿结构; 量子点分散性好, 形貌呈颗粒状. 相似文献
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纳米晶体硅量子点薄膜的制备及表征 总被引:1,自引:0,他引:1
利用激光烧蚀沉积法在n-Si(100)衬底上制备非晶硅(α-Si)薄膜,再经过高温退火技术处理使α-Si晶化成纳米硅晶体(nc—Si)量子点.利用拉曼(naman)L谱仪、X射线衍射仪(XRD)、透射电子显微镜(TEM)以及原子力显微镜(AFM)等测试仪器对nc-Si薄膜进行表征,发现制备的nc-Si量子点排列紧密、尺寸均匀,具有很好的单晶结构,制备的nc-Si薄膜晶化比例很高,并且优先选择在[111]方向晶化. 相似文献
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以巯基丙酸为稳定剂, 在水相中合成了表面带负电荷、具有良好的分散性、平均粒径为5nm的CdTe量子点. 通过CdTe量子点与阳离子聚电解质聚二烯丙基二甲基氯化铵(PDDA)和阴离子聚电解质聚苯乙烯磺酸钠(PSS)之间的静电相互作用, 在石英基片表面通过层层静电自组装方法制备了多层CdTe量子点纳米薄膜. 以荧光分光光度计、UV-Vis、XPS、AFM等测试手段对所得的CdTe量子点纳米薄膜进行了表征. 研究结果表明, CdTe量子点自组装多层薄膜的UV-Vis吸光度与组装层数基本呈线性关系, 薄膜成膜质量良好. 自组装薄膜基本上规整并均匀地覆盖在石英基底表面, 但薄膜中存在部分CdTe量子点聚集现象. 通过在相邻的两层CdTe量子点之间引入基本结构单元为PDDA/PSS/PDDA的聚电解质复合层, 可有效提高CdTe量子点纳米薄膜的成膜质量. 所得的CdTe量子点纳米薄膜具有良好的荧光光致发光性. 相似文献
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Tunable Fabrication of Molybdenum Disulfide Quantum Dots for Intracellular MicroRNA Detection and Multiphoton Bioimaging 下载免费PDF全文
Wenhao Dai Haifeng Dong Bunshi Fugetsu Yu Cao Huiting Lu Xinlei Ma Xueji Zhang 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(33):4158-4164
Molybdenum disulfide (MoS2) quantum dots (QDs) (size <10 nm) possess attractive new properties due to the quantum confinement and edge effects as graphene QDs. However, the synthesis and application of MoS2 QDs has not been investigated in great detail. Here, a facile and efficient approach for synthesis of controllable‐size MoS2 QDs with excellent photoluminescence (PL) by using a sulfuric acid‐assisted ultrasonic route is developed for this investigation. Various MoS2 structures including monolayer MoS2 flake, nanoporous MoS2, and MoS2 QDs can be yielded by simply controlling the ultrasonic durations. Comprehensive microscopic and spectroscopic tools demonstrate that the MoS2 QDs have uniform lateral size and possess excellent excitation‐independent blue PL. The as‐generated MoS2 QDs show high quantum yield of 9.65%, long fluorescence lifetime of 4.66 ns, and good fluorescent stability over broad pH values from 4 to 10. Given the good intrinsic optical properties and large surface area combined with excellent physiological stability and biocompatibility, a MoS2 QDs‐based intracellular microRNA imaging analysis system is successfully constructed. Importantly, the MoS2 QDs show good performance as multiphoton bioimaging labeling. The proposed synthesis strategy paves a new way for facile and efficient preparing MoS2 QDs with tunable‐size for biomedical imaging and optoelectronic devices application. 相似文献
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以葡萄糖和甘氨酸为混合碳源,在较低温度下经水热法一步合成了氮掺杂的荧光碳量子点(N-CQDs),然后对氮掺杂碳量子点的形貌、结构、组成、光学性质和细胞毒性进行了表征,最后将其应用于细胞成像。实验结果表明,对碳量子点进行氮掺杂能有效提高其荧光量子产率,其荧光增强是由于表面形成了大量强供电子基团,当葡萄糖和甘氨酸的质量比为2∶1时能获得最高为6.57%荧光量子产率。氮掺杂碳量子点还具有水溶性好、粒度均匀、优异的光致发光性质、低的细胞毒性、多波长成像等诸多优点,有望作为荧光探针应用于细胞成像等领域。 相似文献
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王婷 《功能材料与器件学报》2012,18(4):297-301
以去铁铁蛋白作为生物模板合成了硒化锌量子点,采用Langmuir-Blodgett技术在硅基质表面制备1:4的EA/SMA的LB薄膜并将硒化锌核铁蛋白吸附组装到EA/SMA薄膜上形成二维阵列。用紫外-可见吸收光谱(UV-Vis)、荧光光谱(PL)、傅里叶转换红外光谱(FTIR)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)进行表征,结果表明成功制备得到了硒化锌量子点核铁蛋白单分子层二维阵列。这种排列在固体表面的有序微观尺寸的纳米结构由于其独特的光学和生物学特性在生物传感、药物和诊断等领域具有潜在的应用前景。 相似文献
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E. H. Sargent 《Advanced materials (Deerfield Beach, Fla.)》2005,17(5):515-522
Colloidal nanocrystals are quantum‐size‐effect tunable; offer an abundance of available surface area for electronic and chemical interactions; and are processible from organic or aqueous solution onto substrates rigid or flexible, smooth or rough, flat or curved, inorganic or organic (including biological), crystalline or amorphous, conducting, semiconducting, or insulating. With the benefit of over a decade's progress in visible‐light‐emitting colloidal‐quantum‐dot synthesis, physical chemistry, and devices, significant progress has recently been made in infrared‐active colloidal quantum dots and devices. This progress report summarizes the state‐of‐the‐art in infrared colloidal quantum dots, with an emphasis on applications and devices. The applications of interest surveyed include monolithic integration of fiber‐optic and free‐space‐communications photonic components with electronic substrates such as silicon and glass; in‐vivo biological tagging in infrared spectral bands in which living tissue is optically penetrable to a depth of 5–10 cm; solar and thermal photovoltaics for energy conversion; and infrared sensing and imaging based on non‐visible, including thermal, signatures. The synthesis and properties of quantum dots are first reviewed: photoluminescence quantum efficiencies greater than 50 % are achievable in solution, and stable luminescent dots are available in organic and aqueous solvents. Electroluminescent devices based on solution processing have been reported with external quantum efficiencies approaching 1 %. Photoconductive devices have been realized with 3 % internal quantum efficiencies, and a photovoltaic effect was recently observed. Electro‐optic modulation achieved by either field‐ or charge‐induced modification of the rate of optical absorption has been demonstrated based both on interband and intersubband (intraband) transitions. Optical gain from these processible materials with a threshold of 1 mJ cm–2 and an optical net modal gain coefficient of 260 ± 20 cm–1 have been reported. 相似文献
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基于量子点具有激发光谱宽、发射光谱窄、荧光量子产率高和寿命长等特殊的性质,被认为是一种比荧光染料分子更理想的生物探针。详细介绍了国内外的几种量子点制备方法及其表面修饰,另外综述了量子点在生物学的应用。 相似文献