共查询到20条相似文献，搜索用时 46 毫秒
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利用水热合成法成功地合成了Tb(OH)3纳米管、Sm(OH)3和Eu(OH)3纳米棒.Tb(OH)3纳米管外径80nm～150 nm,内径20 nm～90 nm,长度可达几个微米;Sm(OH)3和Eu(OH)3纳米棒直径28 nm～35 m,长度只有100nm～500 nm.使用X射线衍射、透射电子显微术及选区电子衍射等分析技术,对这些样品的物相纯度、形貌、晶体结构完整性以及晶体生长方向等进行了详细的表征.在部分Tb(OH)3样品端口处可以发现c轴加倍的超晶格结构.这种结构的形成可由在纳米管的生长过程中铽离子的局域耗尽机理来解释. 相似文献
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ZnO近紫外波长纳米激光器的研究 总被引：1，自引：0，他引：1
随着纳米科技的兴起,纳米激光的研究成为了又一个新的重要课题.ZnO纳米微晶有两种结构可以产生随机激光,一是六角柱形蜂窝状微晶结构,二是颗粒粉末状结构,产生的近紫外激光波长是387.5 nm,光泵浦阈值是50 kW/cm2.采用气相输运的催化外延晶体生长过程来制备ZnO纳米线阵列构成的光致纳米激光器,激光波长383 nm,线宽仅为0.3 nm,光泵浦阈值是40 kW/cm2. 相似文献
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Si基 ZnO纳米壁网格结构紫外探测器的制备 总被引：2，自引：2，他引：0
利用等离子体辅助分子束外延设备在Si（111）衬底上在没有任何催化剂情况下,得到了ZnO纳米壁的网状结构。这些ZnO纳米壁网格结构是c轴择优取向的。纳米结构的厚度为10到20纳米,高度大约为50纳米,这种纳米结构被制成平面的金属-半导体-金属结构的光导型紫外探测器件。这种探测器具有高响应,宽范围的特点。波长从360纳米减小到250纳米的过程中,器件的响应度无明显下降。在5V的偏压下,暗电流小于6μA。ZnO 纳米结构探测器响应峰值出现在360纳米处,其数值为15 A/W。探测器的紫外可见抑制比在2个量级以上。 相似文献
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染料敏化太阳电池以其良好的电池性能、简单的制作工艺、廉价的制作成本等优点越来越受到人们的关注。尝试用水热合成法在透明导电玻璃FTO(SnO2∶F)衬底上一步制备出高度有序的TiO2单晶纳米棒阵列,使用扫描电子显微镜SEM及X射线衍射仪(XRD)等对其进行表征分析。用制备的样品作为光阳极封装电池并对其进行电池性能的测试。用化学浴沉积(CBD)方法对制备的样品进行CdS表面修饰,通过测量其紫外-可见吸收光谱及明暗场的电流-电压特性曲线等考察电池性能随硫化镉修饰次数的变化规律。 相似文献
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用含有硝酸锌(Zn(NO3)2)和六次甲基四胺(HMTA,C6H12N4)的电解液,在低温环境下采用阴极电沉积法在ITO玻璃上成功合成了氧化锌(ZnO)纳米棒阵列。系统研究了电压、前驱物(Zn2+)浓度、温度和种子层等参数对ZnO纳米棒形貌结构的影响,实现了ZnO纳米棒的可控制备。结果表明,在有种子层的情况下,当电压为-0.9V、Zn2+浓度为0.01M、温度为75℃条件下生长的ZnO纳米棒c-轴择优取向好、尺寸均匀(80~100nm),且在380~750nm的可见光波长范围内的透射率达到80%。 相似文献
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利用甲氨铅氯(CH3NH3PbCl3)钙钛矿薄膜直接包覆在垂直二氧化钛纳米棒(TiO2NRs)阵列上的方法,研制了一种灵敏的紫外光电探测器。光响应分析表明,所制备的TiO2NRs阵列/CH3NH3PbCl3钙钛矿核壳异质结对紫外辐射非常敏感,峰值灵敏度在365nm左右,但对波长大于400nm的光照几乎不敏感。在365nm的光照以及2V的偏压下,其响应度和比探测率分别为～50mA/W和～5.39×1010 Jones。此外,该器件表现出良好的环境稳定性。根据我们的理论模拟,相对较好的器件性能与核壳异质结阵列独特的几何结构的显著地光限制效应有关。结果表明,基于TiO2NRs阵列/CH3NH3PbCl3钙钛矿核壳异质结的紫外光电探测器在未来的紫外光电系统中有着潜在的应用前景。 相似文献
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用退火法在玻璃、硅片衬底上先生长ZnO籽晶,然后在90℃下在醋酸锌和六亚甲基四胺溶液中生长了直径约为17 nm的ZnO纳米棒.采用X射线衍射仪(XRD)分析了不同衬底上生长的ZnO纳米棒的结构和择优生长取向,用扫描电子显微镜(SEM)观察了ZnO的形态,用荧光光谱仪分析了纳米棒的发光特性,讨论了籽晶、衬底类型和衬底放置方式对纳米棒的尺寸、排列趋向性和光学性能的影响.纳米棒的直径和排列依赖于衬底的初始状态,籽晶可以减小纳米棒的尺寸,增强纳米棒的排列有序性;一旦衬底上生长了籽晶,后续生长的纳米棒的尺寸、排列和性能与衬底的类型无关,纳米棒都具有强的紫光发射.但衬底的放置方式会影响其上纳米棒的形态,竖直放置的衬底易生长尺寸分布均匀的准有序排列的纳米棒. 相似文献
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为了发展高性能、低成本和结构简单的ZnO紫外 光探测器。在本文中,利用溶液法,制备出ZnO 纳米颗粒,采用透射电子显微镜(TEM)、X射线衍射仪(XRD)、紫外-可见分光光度计和荧光 光谱仪,分别 研究了ZnO纳米颗粒的形貌、晶相结构和光学特性。结果显示:样品呈球形状的颗粒,尺寸 分布在6~8.5nm 之间,平均粒径为7.1nm,为六方纤锌矿结构。发现ZnO纳米颗 粒的陡峭吸收边出现在370nm附近,在390nm 处出现一个很强的近带边发射峰和一宽泛的可见光发光带。此外,利用制备的ZnO纳米颗粒 ,旋涂在刻蚀 有叉指电极的FTO(SnO2:F)上,制备出紫外光探测器,测试了它在暗态和365 nm紫外光照下的电流-电压(I-V) 和电流-时间(I-t)特性。结果表明:紫外光探测器的灵敏度、光响应度、响 应时间、恢复时间分别为62.4(在 －3.5V处),13.6A/W(在+5V处), 15s。另外,它的光响应机理主要由于ZnO纳米 颗粒表面吸附的氧起主导作用。 相似文献
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Using a low temperature hydrothermal synthesis method, ZnO nanorod networks have been directly grown across trenched Au microelectrodes arrays, which were modified with a layer of ZnO seeds. The characteristics of the current-voltage (Ⅰ-Ⅴ) and the photoresponse were obtained both in the dark and under ultraviolet illumination. The bridged nanorod network demonstrated a highly sensitive response to UV illumination in atmosphere at room temperature. It can be useful for nanoscale optoelectronic applications, serving as chemical sensors,biological sensors, and switching devices. 相似文献
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Yong‐Bing Tang Xiang‐Hui Bo Chun‐Sing Lee Hong‐Tao Cong Hui‐Ming Cheng Zhen‐Hua Chen Wen‐Jun Zhang Igor Bello Shuit‐Tong Lee 《Advanced functional materials》2008,18(21):3515-3522
A new catalyst seeding method is presented, in which aerosolized catalyst nanoparticles are continuously self‐assembled onto amine‐terminated silicon substrates in gas phase to realize controllable synthesis of vertically aligned Mg‐doped GaN nanorod arrays on n‐type Si (111) substrates. The diameter, areal density, and length of GaN nanorods can be controlled by adjusting the size of Au nanoparticles, flowing time of Au nanoparticles, and growth time, respectively. Based on the synthesis of p‐type GaN nanorods on n‐type Si substrates, p‐GaN nanorod/n‐Si heterojunction diodes are fabricated, which exhibit well‐defined rectifying behavior with a low turn‐on voltage of ～1.0 V and a low leakage current even at a reverse bias up to 10 V. The controllable growth of GaN nanorod arrays and the realization of p‐type GaN nanorod/n‐type Si heterojunction diodes open up opportunities for low‐cost and high‐performance optoelectronic devices based on these nanostructured arrays. 相似文献
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In this study, we fabricated an ultraviolet (UV) photodetector by blending a hybrid photoactive layer (HPL) that is composed of a hybrid structure containing Carbon Quantum Dots (CQDs) and Zinc Oxide Nanorods (ZnO NRs). To observe the effective photo-inducing abilities of CQDs and ZnO NRs, we analyzed the electrical properties of a UV photodetector using an HPL of CQDs/ZnO NRs. Under an illumination of 365 nm UV light with an intensity of 1 mW/cm2, the UV photodetector exhibited a high detectivity of 8.33 × 1012 Jones, which is higher than that of a UV photodetector using a HPL of blended poly-n-vinylcarbazole (PVK) and ZnO NRs. Experimental results show that an HPL of blended CQDs/ZnO NRs can induce efficient charge extraction from CQDs and ZnO NRs. In addition, CQDs act as charge controllers that enable hole-electron separation in the device upon UV illumination. These results indicate that synthesized CQDs can substitute for a charge transport polymer (i.e., PVK) and that a UV photodetector using CQDs can exhibit high detectivity. 相似文献
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Vertical Schottky ultraviolet photodetector based on graphene and top–down fabricated GaN nanorod arrays 
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下载免费PDF全文 Xuemin Zhang Changling Yan Jinghang Yang Chao Pang Yunzhen Yue Chunhong Zeng Baoshun Zhang 《半导体学报》2022,43(6):062804-1-062804-7
GaN has been widely used in the fabrication of ultraviolet photodetectors because of its outstanding properties. In this paper, we report a graphene–GaN nanorod heterostructure photodetector with fast photoresponse in the UV range. GaN nanorods were fabricated by a combination mode of dry etching and wet etching. Furthermore, a graphene–GaN nanorod heterostructure ultraviolet detector was fabricated and its photoelectric properties were measured. The device exhibits a fast photoresponse in the UV range. The rising time and falling time of the transient response were 13 and 8 ms, respectively. A high photovoltaic responsivity up to 13.9 A/W and external quantum efficiency up to 479% were realized at the UV range. The specific detectivity D* = 1.44 × 1010 Jones was obtained at –1 V bias in ambient conditions. The spectral response was measured and the highest response was observed at the 360 nm band. 相似文献
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Dingwei Li Jiaqi Du Yingjie Tang Kun Liang Yan Wang Huihui Ren Rui Wang Lei Meng Bowen Zhu Yongfang Li 《Advanced functional materials》2021,31(47):2105887
Flexible and air-stable phototransistors are highly demanded for wearable near-infrared (NIR) image sensors. However, advanced NIR sensors via low-cost, solution-based processes remained a challenge. Herein, high-performance inorganic–organic hybrid phototransistors are achieved based on solution processed n-type metal oxide/polymer semiconductor heterostructures of In2O3/poly{5,5′-bis[3,5-bis(thienyl)phenyl]-2,2′-bithiophene-3-ethylesterthiophene]} (PTPBT-ET). The In2O3/PTPBT-ET hybrid phototransistor combines the advantages of both fast electron transport in In2O3 and high photoresponse in PTPBT-ET, showing high saturation mobility of 7.1 cm2 V−1 s−1 and large current on/off ratio of >107. As a result, the phototransistor exhibits high performance towards NIR light sensing with a responsivity of 200 A W−1, a specific detectivity of 1.2 × 1013 Jones, and fast photoresponse with rise/fall time of 5/120 ms. Remarkably, the hybrid phototransistor, without any passivation, demonstrates excellent electrical stability without performance degradation even after 160 days in air. A 10 × 10 phototransistor array is also enabled by virtue of the high device uniformity. Lastly, flexible In2O3/PTPBT-ET phototransistor on polyimide substrate is attained, exhibiting outstanding mechanical flexibility up to 1000 bending/releasing cycles at a bending radius of 5 mm. These achievements pave the way for constructing air-stable hybrid phototransistors for flexible NIR image sensor applications. 相似文献
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Yongkai Wang Xiaoyu Liu Qiqian He Gaoyu Chen Dongdong Xu Xudong Chen Wenbo Zhao Jianchun Bao Xiangxing Xu Junli Liu Xun Wang 《Advanced functional materials》2021,31(22):2011251
CsPbX3 (X = Cl, Br, I) perovskite nanowires and nanorods are important 1D and quasi 1D semiconductor nanomaterials. They have shown significant prospect in optic and optoelectronic applications, especially for their adaptability to flexible devices, good carrier transport performance, polarized absorption, and emission properties. Due to the high dependence of the property to the morphology, it is crucial to develop synthesis methods with continuous diameter and length tunability of the 1D/quasi 1D perovskites. In this report, a feasibly room temperature synthesis method was developed for ultrathin CsPbX3(X = Cl, Br, I) perovskite nanowires. By aging the CsPbBr3 nanowires (≈2*500 nm) under ambient condition with proper concentration and time, the nanowires are transformed to nanorods with controllable diameter and length. Reversibly, the nanorods can be transformed back to nanowires. Equilibrium mechanism is adopted to understand the morphology evolution, and hopefully could be generally applied to many other nano materials. The polarized optoelectronic properties of the nanowires and nanorods are interpreted by a model based on the two-channel anisotropies measurement. Polarized light detectors constructed by oriented assembled nanowires are fabricated to demonstrate their application potentials. 相似文献
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Jingjing Lu Dapeng Liu Jiachen Zhou Yingli Chu Yantao Chen Xiaohan Wu Jia Huang 《Advanced functional materials》2017,27(20)
The thin‐film structures of chemical sensors based on conventional organic field‐effect transistors (OFETs) can limit the sensitivity of the devices toward chemical vapors, because charge carriers in OFETs are usually concentrated within a few molecular layers at the bottom of the organic semiconductor (OSC) film near the dielectric/semiconductor interface. Chemical vapor molecules have to diffuse through the OSC films before they can interact with charge carriers in the OFET conduction channel. It has been demonstrated that OFET ammonia sensors with porous OSC films can be fabricated by a simple vacuum freeze‐drying template method. The resulted devices can have ammonia sensitivity not only much higher than the pristine OFETs with thin‐film structure but also better than any previously reported OFET sensors, to the best of our knowledge. The porous OFETs show a relative sensitivity as high as 340% ppm?1 upon exposure to 10 parts per billion (ppb) NH3. In addition, the devices also exhibit decent selectivity and stability. This general and simple strategy can be applied to a wide range of OFET chemical sensors to improve the device sensitivity. 相似文献
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Weilin Liu Yixue Niu Qiusong Chen Hanxiao Jiang Fan Xu Guodong Zhu 《Advanced Electronic Materials》2019,5(12)
In recent years human–machine interaction has become increasingly important in industrial applications and daily life. Proximity sensors are expected to become an important part of such systems. The mechanisms of these sensors are usually based on ultrasound, capacitance, triboelectric effect, optical imaging or semiconducting devices. The fabrication and sensing performance of solution‐based organic transistor proximity sensors is reported. To enhance electrical performance, nanogroove templates are introduced to guide the oriented growth of organic semiconducting layer. The templates are realized by friction‐transferring polytetrafluoroethylene thin layers onto SiO2/Si substrates. An extended gate structure for proximity sensing is designed, in which one end of a silver wire is electrically connected with the gate of the transistor and the other end serves as the sensing end. Proximity sensing is characterized by bringing various charged stimuli close to the sensor and recording the resulting change in drain current. The sensor showed good repeatability during the approach and withdrawal of a stimulus. A maximum current response of 2.2 μA between distances of 3 mm and 53 mm and distance sensitivity of 2.5 nA mm‐1 at a distance of 13 mm are obtained when a charged polytetrafluoroethylene rod is moved up and down above the sensing end. 相似文献
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Cody J. Landry Fraser P. Burns Felix Baerlocher Khashayar Ghandi 《Advanced functional materials》2018,28(19)
Gravity and magnetism are implemented to change the morphology of zinc oxide nanorod sensors during synthesis. The effects of gravity and magnetism can translate into future application of these nanorods through cost‐effective, environmentally friendly, and easy‐to‐use biosensor technology with the quickest available sensing. The sensors can pave the way toward detection of both bacteria and fungi present on the surface with high sensitivity. This ability to sense microorganisms in a “non‐solution‐based” environment represents a key step forward in the fields of health and food safety, as well as solid‐state nanomaterial biotechnology applications. Hundreds of thousands of people are affected each year by accidental contamination and current protocols are far from preventative. The results of the magnetic field studies when compared with previous results show that the following factors affect the outcome of applying magnetic field during the growth of nanorods on their morphology: the direction of growth with respect to gravity, the method of seeding, and the substrate. 相似文献
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Seong-Yong Jeong Young Kook Moon Jin Koo Kim Sei-Woong Park Yong Kun Jo Yun Chan Kang Jong-Heun Lee 《Advanced functional materials》2021,31(6):2007895
Water poisoning, the dependence of gas-sensing characteristics on moisture, in oxide chemiresistors remains a long-standing challenge. Various approaches are explored to mitigate water poisoning but they are often accompanied by significant deterioration of sensing capabilities such as gas response deterioration, gas selectivity alteration, and sensor resistance increase up to unmeasurable levels. Herein, a novel sensor design with a moisture-blocking Tb4O7 overlayer is suggested as a facile and universal strategy to remove moisture poisoning without sacrificing intrinsic sensing properties. A submicrometer-thick coating of Tb4O7 overlayer on In2O3 sensors effectively eliminates the humidity dependence of the gas-sensing characteristics without significantly altering the gas response, selectivity, and sensor resistance. Furthermore, the general validity of the water-blocking effect using the Tb4O7 overlayer is confirmed in diverse gas sensors using SnO2, ZnO, and Pd/SnO2. The negligible moisture interference of the bilayer sensor is explained in terms of the hydrophobic nature of the Tb4O7 overlayer and the prevention of formation of the OH radical by the interaction between Tb4O7 and In2O3. A universal solution to design diverse humidity-independent gas sensors with different gas selectivities can open up new pathways toward building accurate and robust gas sensors with new functionalities and high-performance artificial olfaction. 相似文献