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1.
采用超高真空化学气相沉积( UHV/CVD)技术在Si衬底上外延生长了PIN结构多层Ge量子点探测器材料。 PIN探测器结构由N型Si衬底,多层Ge量子点吸收区,和原位掺杂P型Si盖层构成,电极分别制作于N-Si和P-Si上,以获得好的欧姆接触。制备的Si基Ge量子点光电探测器具有较低的暗电流密度(-1 V偏压下为7.35×10-6 A/cm2),与Si相比,探测波长延伸到1.31μm波段。  相似文献   

2.
硒化铅纳米结构材料因其多激子产生效应、快速光敏吸收和近红外发射而被广泛应用于太阳能电池和光电探测器,并成为探测器领域的研究热点。在制备硒化铅量子点的基础上,通过退火工艺得到了一种新型的纳米材料融合量子点。所需的最佳退火温度可以有效减少缺陷,提高融合量子点的活性。为了体现融合量子点与其他材料相比的优势,采用旋涂法制备薄膜并用于光电导器件的研制。退火温度从室温提高到470℃,通过透射电子显微镜观察了不同温度下硒化铅量子点的融合现象,并研究了量子点退火对光电导器件性能的影响。量子点之间的平均距离随着退火温度的升高而减小,这增强了量子点之间的相互融合。实验数据表明,硒化铅活性层的最佳退火温度为310℃,开关比K和响应度R在310℃时达到最大值,响应度增加3倍以上。这是因为硒化铅活性层中载流子的迁移率增强。并成功制备了光电导探测器Au/PbSe融合量子点/Au(100 nm),为后续制备新的量子点器件奠定了基础。  相似文献   

3.
PbS胶体量子点因其光吸收系数高、制备成本低、沉积工艺简单、带隙可调等优点,成为备受关注的新型红外探测纳米材料。光电二极管结构的PbS量子点光电探测器通常使用高透过率、高电子迁移率的ZnO来制备N型层,以加快光生载流子的分离和提取。但是通过溶胶-凝胶法制备的ZnO薄膜在制备过程中会在薄膜中产生缺陷,限制ZnO层性能的发挥。本文通过调节ZnO前驱体溶液的浓度成功制备出缺陷更低的ZnO薄膜并应用于ZnO/PbS光电探测器件,经测试,当溶液浓度为0.7M(mol/L)时,所制备的器件表现出最佳的性能,在1 600 nm处的响应度和探测率分别为0.32A/W和3.48×1011Jones,外量子效率为25%,器件的响应时间为τR=130μs,τF=20μs。这项工作为PbS量子点光电器件性能的优化提供了新的解决方案。  相似文献   

4.
比热是Si3N4薄膜重要的热学参数之一,Si3N4薄膜比热特性研究对热传原理传感器研究和发展以及物质微尺度热学特性的研究有重要的意义.本研究设计并制作出一种悬膜结构,从理论上分析了此结构的传热机理,并通过实验测得Si3N4薄膜的比热,最后分析了此测量系统存在的误差及解决方法.  相似文献   

5.
目前InGaAs等材料的短波红外探测器读出电路已经较为成熟,其输入级接口电路也因不同公司和项目需求有着相对成熟的选择,但是在量子点短波红外探测器读出电路输入级接口电路的选择上,现有可查阅的公司及团队也并没有对输入级接口电路的选择进行研究,为了解决量子点探测器与读出电路输入级接口的匹配问题,对量子点探测器所使用的主流读出电路输入级结构进行研究,如CTIA、BDI,通过建立其电路等效模型并进行详细分析,以注入效率为切入点进行公式的研究与推导,将量子点探测器测试所得IV、CV分别结合不同输入级电路结构进行计算及对比,选择出一个更适合量子点探测器的读出电路输入级结构,最终选择CTIA型电路作为量子点短波红外探测器读出电路的输入级接口,其注入效率大于99%。  相似文献   

6.
利用射频磁控溅射技术在SiO2/n—Si和玻璃衬底上制备ZnO薄膜,研究了溅射气体氩氧比对薄膜特性的影响,在氩氧比为2:3下所制备的ZnO薄膜c轴择优取向相对较好,薄膜的颗粒随氩氧比的增加而增大,所制备的薄膜在可见光均具有较高的透射率,吸收边在360-380nm附近;并在以SiO。/n—Si为衬底,氩氧比为2:3,经过退火处理的ZnO薄膜上制作Ag-ZnO—Ag肖特基MSM叉指结构的紫外探测器,所制作的探测器在5V偏压下漏电流为3.3×10^-8A,在紫外波段有较高的响应度,光响应度峰值在365nm附近。  相似文献   

7.
该文在ITO电极表面组装TiO2和CdS量子点,构建用于三硝基甲苯(TNT)气体现场快速检测的ITO/TiO2/CdS传感器.通过该传感器对TNT气体吸附前后电位变化的研究,探讨爆炸物气体分子与量子点纳米材料的结合形式以及TNT气体分子在CdS和TiO2表面所发生的反应过程和传感机理.该传感器响应速度快,灵敏度高,在恒电流6 mA条件下,TNT气体浓度在15~1 500 μg/L范围内与传感器响应呈良好的线性关系,最低检测限为7μg/L(S/N=3).该工作初步研究了TNT爆炸物传感器的制备、优化条件和响应机理.该类传感器在应对突发性事件的发生、维护公共安全和人民健康等方面将会具有广阔的应用前景.  相似文献   

8.
硅基硅锗材料由于与成熟的硅微电子工艺兼容,加上优越的性能,在硅基光电子器件如光电探测器、场效应晶体管等方面得到了广泛的应用。III-Ⅴ族半导体材料在1.3~1.55μm具有较大的吸收系数,是理想的吸收区材料;然而,III-Ⅴ族半导体材料价格昂贵、导热性能不好,机械性能较差,并且与现有成熟的硅基工艺兼容性差,限制了其在光电集成技术中的应用。而Si Ge材料与Si基微电子器件的制作工艺相兼容,应变的外延Ge材料吸收波长扩展到了1.6μm以上,因此研究Si基外延纯Ge探测器引起人们极大兴趣。本文综述了硅基硅锗材料在探测器研制及材料制备方面的主要进展情况。  相似文献   

9.
本文主要回顾了石墨烯量子点的制备以及基于石墨烯量子点自旋和电荷量子比特操作的研究进展,由于石墨烯材料相对较轻的原子重量使其具有较小的自旋轨道相互作用,另外含有核自旋的碳同位素13C在自然界中的含量大约只占1%,这使得超精细相互作用(即核自旋和电子自旋相互作用)较弱,所以石墨烯比其他材料具有较长的自旋退相干时间,在量子计算和量子信息中有非常好的应用前景.本文计算了5种静电约束制备的石墨烯量子点:1)扶手型单层石墨烯纳米条带,2)单层石墨烯圆盘,3)双层石墨烯圆盘,4)ABC堆积型三层石墨烯圆盘,5)ABA堆积型三层石墨烯圆盘.石墨烯量子点中自旋比特应用的关键是破坏谷简并,在1)中,主要是利用边界条件破坏谷简并,而2)–5)中是利用外磁场破坏谷简并.文章进一步介绍了自旋轨道相互作用和超精细相互作用对石墨烯量子点中自旋操作的影响.  相似文献   

10.
介绍了荧光和磷光纳米材料的种类,如无机半导体量子点,金属离子掺杂的半导体量子点,金属纳米粒子或纳米簇,硅点,碳点和石墨烯点等。接着阐述了这些纳米材料的光致发光的光物理机制和猝灭或增强的一般性原理。最后简要综述了量子点或纳米材料发光的猝灭或增强现象在化学传感中的应用和具体的响应机理。  相似文献   

11.
In this work, the vertical structure photodetector based on CsPbBr3 quantum dots (QDs) with a structure of indium tin oxide (ITO)/zinc oxide (ZnO)/CsPbBr3 QDs/Au is reported. In this device, CsPbBr3 QDs film works as the light‐harvesting layer, and ZnO QDs film acts as the electron transport channel, which can extract the electron efficiently and improve the quality of CsPbBr3 QDs film. As a result, the on/off ratio, detectivity and rise time (decay time) of CsPbBr3/ZnO hybrid photodetector are measured to be 2.4 × 106, 2.25 × 1011, and 62 milliseconds (82 ms) under 0‐V bias. This work inspires the development of vertical structure photodetectors based on the all‐inorganic perovskite QDs.  相似文献   

12.
Cathodoluminescent imaging of the visible light emitted from quantum dots is reported. The shape and uniformity of individual particles is observed in the scanning transmission electron microscope image, and the image of the particles created from their visible light collected simultaneously is shown. Visible light images of the 13 nm sized particles are reported for clusters of particles. The emission spectrum collected from small clusters of quantum dots is also reported.  相似文献   

13.
纳米金的电检测方法与免疫检测中的应用   总被引:3,自引:0,他引:3  
免疫亲和反应引起的导电性的改变比较微弱,难以进行电检测。通过采用纳米金修饰羊抗兔IgG,以及免疫反应,形成抗原-抗体-纳米金复合体,该复合体有序聚集成量子点阵列,改变了电荷输运途径并提高导电性,实现免疫反应的电检测。采用纤维素薄膜作为固相载体,以夹心结构实现免疫渗滤,用双环金电极进行交流阻抗谱检测。工作频率为20Hz-1MHz。实验结果表明,导电性不受游离纳米金粒子影响,随着纳米金生物复合体的密度增加而增高。IgG的检测下限可达到10r/mL,工作频率为100m时具有最高的灵敏度。最后,通过掺杂实验表明,掺杂的Ag离子增加低频时的导电性,使交流阻抗谱趋于平坦。  相似文献   

14.
Quantum dot light‐emitting devices (QLEDs), originally developed for displays, were recently demonstrated to be promising light sources for various photomedical applications, including photodynamic therapy cancer cell treatment and photobimodulation cell metabolism enhancement. With exceptional emission wavelength tunability and potential flexibility, QLEDs could enable wearable, targeted photomedicine with maximized absorption of different medical photosensitizers. In this paper, we report, for the first time, the in vitro study to demonstrate that QLEDs‐based photodynamic therapy can effectively kill Methicillin‐resistant Staphylococcus aureus, an antibiotic‐resistant bacterium. We then present successful synthesis of highly efficient quantum dots with narrow spectra and specific peak wavelengths to match the absorption peaks of different photosensitizers for targeted photomedicine. Flexible QLEDs with a peak external quantum efficiency of 8.2% and a luminance of over 20,000 cd/m2 at a low driving voltage of 6 V were achieved. The tunable, flexible QLEDs could be employed for oral cancer treatment or diabetic wound repairs in the near future. These results represent one fresh stride toward realizing QLEDs' long‐term goal to enable the wide clinical adoption of photomedicine.  相似文献   

15.
We examine coherent processes in a two-state quantum system that is strongly coupled to a mesoscopic spin bath and weakly coupled to other environmental degrees of freedom. Our analysis is specifically aimed at understanding the quantum dynamics of solid-state quantum bits such as electron spins in semiconductor structures and superconducting islands. The role of mesoscopic degrees of freedom with long correlation times (local degrees of freedom such as nuclear spins and charge traps) in qubit-related dephasing is discussed in terms of a quasi-static bath. A mathematical framework simultaneously describing coupling to the slow mesoscopic bath and a Markovian environment is developed and the dephasing and decoherence properties of the total system are investigated. The model is applied to several specific examples with direct relevance to current experiments. Comparisons to experiments suggests that such quasi-static degrees of freedom play an important role in current qubit implementations. Several methods of mitigating the bath-induced error are considered.Dedicated to Anton Zeilinger, whose work has inspired exploration of quantum phenomenon in many avenues of physics and beyond.  相似文献   

16.
碳量子点作为一种新型的碳纳米荧光材料,由于其具有生物相容性好等优点而备受关注。该文以乙二胺为原料,通过电化学方法,制备了一种含氮碳量子点。该含氮碳量子点,同时具有单光子和双光子荧光响应特性,且耐光漂白和pH稳定。利用Cu2+对所制备的含氮碳量子的荧光淬灭特性于离子检测的试验表明,该含氮碳量子点可用于微量Cu2+的定量分析。  相似文献   

17.
量子点荧光标记技术在生物医学领域的应用   总被引:4,自引:0,他引:4  
量子点作为一种新型的纳米荧光材料在生物学领域的应用已引起国际上的普遍关注,量子点独特的荧光性能使其在这一领域的应用有着无可比拟的优越性.该文主要就量子点的荧光性能,基于量子点标记的生物荧光探针的制备及其在生物医学领域中的应用研究进展作一概述.  相似文献   

18.
The patterning of quantum dot light-emitting diodes (QLED) is essential for QLED in the display application. In the work, we studied patterning thin film to form IGZO electron transport layers for QLED. Making use of a staggered IGZO film as the electron transport layer, we studied QLED degradation and observed luminance inversion, which is due to the non-uniform current spreading effect caused by the staggered IGZO film. The current crowding at the thinner film area (with lower electric resistance) leads to a patterned emission of the device but also a faster device degradation at the same time.  相似文献   

19.
Three effective detection systems for glucose based on reversible “on-off” fluorescence recognition mechanism were developed. Fluorescent quantum dot (FQD) with amino and carboxyl groups were used as fluorescent reported section and its fluorescence was modified by boronic acid functional benzyl viologens (BBVs). The BBVs acted as both quenchers and receptors roles in these systems. The sensing systems of FQD/BBVs all displayed higher detection efficiency for glucose than organic-dye/BBVs system, especially for FQD/o-BBV sensing system. The glucose response signal showed 4-fold fluorescent intensity increase of FQD/o-BBV system only in the presence of 10.0 mM glucose.  相似文献   

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