生长温度对ZnO薄膜晶体质量和发光特性的影响

采用激光脉冲沉积法在Si(100)衬底上生长ZnO薄膜,衬底温度分别为室温,200℃,300℃,400℃和500℃.用X射线衍射仪、拉曼光谱、扫描电子显微镜对薄膜的微结构进行了测量,并测量了室温下薄膜的光致发光特性.结果表明,300℃时.ZnO具有最佳择优取向,随着衬底温度升高.衍射峰半峰全宽减小,薄膜晶粒尺寸增大,400℃时,薄膜具有各向等大的品粒尺寸.同时拉曼谱结果显示,薄膜内部的缺陷随衬底温度变化无明显差别,应力表现为张应力,400℃时应力最小,紫外发光峰在衬底温度为400℃时最强,而黄绿光带最弱.在减少薄膜缺陷,提高择优长向和晶粒尺寸的同时.使晶粒横向尺寸和纵向尺寸尽可能相同,可极大提高薄膜的发光特性.     

原位衰减全反射表面增强红外光谱实验技术

介绍了原位研究电极,溶液界面反应的技术--衰减全反射表面增强红外光谱实验技术(ATR-SEIRAS)的产生背景和工作原理,重点描述了ATR-SEIRAS实验技术的关键:光谱电化学池的构造和薄膜电极的制备.与IRAS相比,ATR-SEIRAS技术可以更容易消除溶剂的背景吸收,获得较高的表面灵敏度,而且允许物质在电极表面自由扩散.与循环伏安相结合,利用ATR-SEIRAS技术可以实时监测电极,溶液界面问的反应.选择了利用ATR-SEIRAS实验技术原位研究功能表面的构造和性质、分子识别和反应中间体的形成等方面的应用实例,分析了ATR-SEIRAS实验技术的研究方向.     

Fabrication of SU-8 based microchip electrophoresis with integrated electrochemical detection for neurotransmitters

A new SU-8 based microchip capillary electrophoresis (MCE) device has been developed for the first time with integrated electrochemical detection. Embedded electrophoretic microchannels have been fabricated with a multilayer technology based on bonding and releasing steps of stacked SU-8 films. This technology has allowed the monolithic integration in the device of the electrochemical detection system based on platinum electrodes. The fabrication of the chips presented in this work is totally compatible with reel-to-reel techniques, which guarantee a low cost and high reliability production. The influence of relevant experimental variables, such as the separation voltage and detection potential, has been studied on the SU-8 microchip with an attractive analytical performance. Thus, the effective electrical isolation of the end-channel amperometric detector has been also demonstrated. The good performance of the SU-8 device has been proven for separation and detection of the neurotransmitters, dopamine (DA) and epinephrine (EP). High efficiency (30,000-80,000 N/m), excellent precision, good detection limit (450 nM) and resolution (0.90-1.30) has been achieved on the SU-8 microchip. These SU-8 devices have shown a better performance than commercial Topas (thermoplastic olefin polymer of amorphous structure) microchips. The low cost and versatile SU-8 microchip with integrated platinum film electrochemical detector holds great promise for high-volume production of disposable microfluidic analytical devices.     

Formation of solid electrolyte films on porous supporting electrodes

In this work, the method of chemical deposition from the gas phase of organometallic compounds (CVDOM) was used to obtain thin electrolyte films of zirconia stabilized by yttria (YSZ) on a supporting electrode. Tetrakis(2,2,6,6-tetramethyl-3,5-heptanedionato)zirconium and tris(2,2,6,6-tetramethyl-3,5-heptanedionato)yttrium often termed as zirconium (IV) Zr(dpm)₄ and yttrium (III) Y(dpm)₃ dipivaloylmethanates were used as precursors for film deposition. Gas-tight electrolyte films were obtained on a supporting anode with a thickness of 4–10 μm at moderate deposition temperatures of 500–700°C. An electrochemical cell was prepared and tested using the obtained films. The cell allowed obtaining the power density values of 680, 360, and 175 mW/cm² at the temperatures of 800, 700, and 600°C, accordingly.     

Design of periodic metal-insulator-metal waveguide back structures for the enhancement of light absorption in thin-film solar cells

To increase the absorption in a thin layer of absorbing material (amorphous silicon, a-Si), a light trapping design is presented. The designed structure incorporates periodic metal-insulator-metal waveguides to enhance the optical path length of light within the solar cells. The new design can result in broadband optical absorption enhancement not only for transverse magnetic (TM)-polarized light, but also for transverse electric (TE)-polarized light. No plasmonic modes can be excited in TE-polarization, but because of the coupling into the a-Si planar waveguide guiding modes and the diffraction of light by the bottom periodic structures into higher diffraction orders, the total absorption in the active region is also increased. The results from rigorous coupled wave analysis show that the overall optical absorption in the active layer can be greatly enhanced by up to 40%. The designed structures presented in this paper can be integrated with back contact technology to potentially produce high-efficiency thin-film solar cell devices.     

Review of flexible and transparent thin-film transistors based on zinc oxide and related materials

Flexible and transparent electronics enters into a new era of electronic technologies.Ubiquitous applications involve wearable electronics,biosensors,flexible transparent displays,radio-frequency identifications(RFIDs),etc.Zinc oxide(ZnO) and relevant materials are the most commonly used inorganic semiconductors in flexible and transparent devices,owing to their high electrical performances,together with low processing temperatures and good optical transparencies.In this paper,we review recent advances in flexible and transparent thin-film transistors(TFTs) based on ZnO and relevant materials.After a brief introduction,the main progress of the preparation of each component(substrate,electrodes,channel and dielectrics) is summarized and discussed.Then,the effect of mechanical bending on electrical performance is highlighted.Finally,we suggest the challenges and opportunities in future investigations.     

柔性低温多晶硅薄膜晶体管的弯曲稳定性

研究了以聚酰亚胺为基板的p型低温多晶硅薄膜晶体管在不同弯曲半径下的偏压稳定性。当曲率半径从15 mm变到3 mm时,在拉伸弯曲状态下,阈值电压和平坦时保持一致(Vth=-1.34 V),迁移率μsat从45.65 cm~2/(V·s)降到45.17 cm~2/(V·s),开关比增大;在压缩弯曲状态下,转移特性曲线和平坦状态保持了非常好的一致性。在最小弯曲半径为3 mm时,进行了正负偏压稳定性测试,结果表明,器件依然具有很好的稳定性。     

Peeling behavior of a viscoelastic thin-film on a rigid substrate

In order to study the adhesion mechanism of a viscoelastic thin-film on a substrate, peeling experiment of a viscoelastic polyvinylchloride (PVC) thin-film on a rigid substrate (glass) is carried out. The effects of peeling rate, peeling angle, film thickness, surface roughness and the interfacial adhesive on the peel-off force are considered. It is found that both the viscoelastic properties of the film and the interfacial adhesive contribute to the rate-dependent peel-off force. For a fixed peeling rate, the peel-off force decreases with the increasing peeling angle. Increasing film thickness or substrate roughness leads to an increase of the peel-off force. Viscoelastic energy release rate in the present experiment can be further predicted by adopting a recently published theoretical model. It is shown that the energy release rate increases with the increase of peeling rates or peeling angles. The results in the present paper should be helpful for understanding the adhesion mechanism of a viscoelastic thin-film.     

低温制备具有强荧光性能三氧化钼纳米带水溶胶

通过过氧化途径,在低温(100℃)且不使用模板和有机溶剂的条件下,成功制备了具有良好荧光性能的三氧化钼(MoO3)纳米带水溶胶.利用X射线衍射仪(XRD)、透射电子显微镜(TEM)、高分辨透射电子显微镜(HRTEM)、荧光光谱仪、荧光显微镜等表征手段对所制备溶胶的结构及性能进行了表征.结果显示,溶胶是由长度约为100μm,宽度为50nm到100nm,厚度小于10nm的MoO3纳米带组成.所制备的溶胶烘干后可以得到大面积的MoO3纳米带薄膜,薄膜具有很好的韧性.荧光光谱图及荧光显微镜照片显示,纳米带溶胶及干燥后所得到的自支撑(free standing)纳米带薄膜均具有良好的荧光性能,表明其在光学成像、传感及LED等方面具有很好的应用前景.     

光学薄膜鲁棒设计中膜系误差灵敏度控制

提出了一种基于膜系误差灵敏度控制的鲁棒膜系设计方法,建立了鲁棒膜系设计评价函数在膜层参数误差统计分布下的解析表达式,避免统计样本数目有限性造成的样本均值与总体期望的误差,以及过大数目样本造成的长的计算时间消耗,并通过宽带增透膜、中性分光膜和线性透射率滤光片等多种薄膜的鲁棒设计实验证实了其在膜层参数误差控制上的效果。结果表明:该新型鲁棒膜系设计方法具有内在的快速算法特性,其设计膜系对镀膜中的膜厚监控误差不敏感,对于高质量薄膜的重复制备和批量成品率的提高具有实用价值。