分别采用一步水热法和两步水热法在导电玻璃（FTO）上制备了二氧化钛（TiO 2 ）纳米棒（NR）阵列和TiO 2 分枝纳米棒（B-NR）阵列。利用低温化学浴沉积法（CBD）在TiO 2 纳米棒阵列（NRA）和TiO 2 分枝纳米棒阵列（B-NRA）基底上沉积Sb 2 S 3 纳米粒子（NPs）。接着分别旋涂聚-3已基噻吩（P3HT）和2,2′7,7′-四-（二甲氧基二苯胺）螺芴（Spiro-OMeTAD）组装成TiO 2 （NRA）/Sb 2 S 3 /P3HT/Spiro-OMeTAD和TiO 2 （B-NRA）/Sb 2 S 3 /P3HT/Spiro-OMeTAD为光活性层的杂化太阳电池。结果表明,由TiO 2 （NRA）/Sb 2 S 3 /P3HT/Spiro-OMeTAD复合膜结构组装的杂化太阳电池的光电转换效率（PCE）是2.92%,而由TiO 2 （B-NRA）/Sb 2 S 3 /P3HT/Spiro-OMeTAD复合膜结构组装的杂化太阳电池的PCE提高到了4.67%。

采用两步水热法在导电玻璃(FTO)上制备TiO2分枝纳米棒(B-NR)阵列.利用低温化学浴沉积法(CBD)在TiO2分枝纳米棒阵列(B-NRA)基底上沉积Sb2 S3纳米粒子(NPs).接着分别旋涂P3 HT和Spiro-OMeTAD组装成TiO2(B-NRA)/Sb2 S3/P3 HT/Spiro-OMeTAD为光活性层的杂化太阳电池.通过对杂化太阳电池的光电性能测试,结果表明,TiO2分枝纳米棒阵列具有高的吸光强度,较大的比表面积和多级电荷传输通道,由TiO2(B-NRA)/Sb2 S3/P3 HT/Spiro-OMeTAD复合膜结构组装的杂化太阳电池的能量转换效率(PCE)是4.67％.

In order to reduce the charge recombination and improve the performance of hybrid solar cells, the mixture of P3HT and Spiro-OMeTAD is used as the photoactive layer and hole-transport layer, and is spun onto TiO2 nanorod/Sb2S3 nanoparticles composite film to prepare a hybrid solar cell. By means of SEM, UV visible absorption spectrum, XRD, electrochemical impedance spectroscopy, and steady-state fluorescence spectrum and J-V curve, the microstructure and photovoltaic performance of the hybrid solar cell are characterized and tested. The results show that the hybrid solar cell with the mixture ratio of P3HT and Spiro-OMeTAD of 15 mg/1 mL has a lower charge recombination rate, a longer electron life and the power conversion efficiency is 4.57%.The prepared hybrid solar cell has excellent performance and good application prospect.

Nickel-rich ternary layered transition metal oxide positive materials have attracted much attention due to their high specific capacity, low price and environmental friendliness. However, the material itself has problems such as cyclic capacity degradation, which are caused by Li/Ni mixing, phase change reaction, gas generation, microcracks, transition metal dissolution and surface structure changes. In order to solve the problems of rapid capacity degradation and poor high-temperature performance of positive materials, modification methods of nickel-rich ternary layered transition metal oxide positive materials at home and abroad in recent years were summarized, including optimization methods such as surface coating material synthesis, element doping material preparation, core-shell structure material development, and concentration gradient material design, etc. It is pointed out that the wide application of high nickel layered transition metal oxide anode materials needs to start from the aspects of continuously improving the material preparation method, changing the material properties, and reducing the material cost, etc. to develop high energy density lithium ion batteries, so that nickel-rich ternary layered transition metal oxide anode materials can be applied in the field of power batteries as soon as possible.

A semiclassical method is used to simulate the characteristics of vertical carbon nanotube field-effect transistors on p-GaAs. The calculation results show unique transfer characteristics that depend on the sign of the drain voltage. The transistors exhibit p-type characteristics and ambipolar characteristics for a positive drain voltage and a negative drain voltage, respectively. The p-type characteristics do not change with the GaAs bandgap and doping level, because the hole current from the single-walled carbon nanotube (SWCNT) and drain side dominates the whole current. In contrast, the ambipolar characteristics are greatly influenced by the GaAs bandgap and doping level. Only the electron current in the ambipolar characteristics increases as the GaAs bandgap decreases. Increasing the p-type doping of GaAs increases the p-branch current and decreases the electron current (n-branch) of the ambipolar characteristics. The effects of the SWCNT bandgap and doping level are different from those of GaAs, and the impact of SWCNT on the p-type characteristics is much greater than the impact on the ambipolar characteristics. The p-type current increases as the SWCNT bandgap decreases.

A wet-chemical surface texturing technique, including a two-step metal-catalyzed chemical etching (MCCE) and an extra alkaline treatment, has been proven as an efficient way to fabricate high-efficiency black multicrystalline (mc) silicon solar cells, whereas it is limited by the production capacity and the cost cutting due to the complicated process. Here, we demonstrated that with careful control of the composition in etching solution, low-aspect-ratio bowl-like nanostructures with atomically smooth surfaces could be directly achieved by improved one-step MCCE and with no posttreatment, like alkali solution. The doublet surface texture of implementing this nanobowl structure upon the industrialized acidic-textured surface showed concurrent improvement in optical and electrical properties for realizing 18.23% efficiency mc-Si solar cells (156 mm × 156 mm), which is sufficiently higher than 17.7% of the solely acidic-textured cells in the same batch. The one-step MCCE method demonstrated in this study may provide a cost-effective way to manufacture high-performance mc-Si solar cells for the present photovoltaic industry.

Plasmonic metamaterial absorbers (PMAs) have attracted considerable attention for developing various sensing devices. In this work, we design, fabricate and characterize PMAs of different geometrical shapes operating in mid-infrared frequencies, and explore the applications of the PMAs as sensor for thin films. The PMAs, consisting of metal-insulator-metal stacks with patterned gold nanostructured surfaces (resonators), demonstrated high absorption efficiency (87 to 98 %) of electromagnetic waves in the infrared regime. The position and efficiency of resonance absorption are dependent on the shape of the resonators. Furthermore, the resonance wavelength of PMAs was sensitive to the thin film coated on the surface of the PMAs, which was tested using aluminum oxide (Al2O3) as the film. With increase of the Al2O3 thickness, the position of resonance absorption shifted to longer wavelengths. The dependence of the resonant wavelength on thin film thickness makes PMAs a suitable candidate as a sensor for thin films. Using this sensing strategy, PMAs have potential as a new method for thin film detection and in situ monitoring of surface reactions.

Single-walled carbon nanotube (SWNT) is expected to be a very promising material for flexible and transparent driver circuits for active matrix organic light emitting diode (AM OLED) displays due to its high field-effect mobility, excellent current carrying capacity, optical transparency and mechanical flexibility. Although there have been several publications about SWNT driver circuits, none of them have shown static and dynamic images with the AM OLED displays. Here we report on the first successful chemical vapor deposition (CVD)-grown SWNT network thin film transistor (TFT) driver circuits for static and dynamic AM OLED displays with 6 × 6 pixels. The high device mobility of ~45 cm 2 V −1 s −1 and the high channel current on/off ratio of ~10 5 of the SWNT-TFTs fully guarantee the control capability to the OLED pixels. Our results suggest that SWNT-TFTs are promising backplane building blocks for future OLED displays.

The InGaN/GaN quantum-disks-in-nanowire light-emitting diode (LED) with emission centered at ∼830nm, the longest emission wavelength ever reported in the InGaN/GaN system, and spectral linewidth of 290nm, has been fabricated with p-side-down on a Cu substrate.

A vertical carbon nanotube field-effect transistor (CNTFET) based on silicon (Si) substrate has been proposed and simulated using a semi-classical theory. A single-walled carbon nanotube (SWNT) and an n-type Si nanowire in series construct the channel of the transistor. The CNTFET presents ambipolar characteristics at positive drain voltage (Vd) and n-type characteristics at negative Vd. The current is significantly influenced by the doping level of n-Si and the SWNT band gap. The n-branch current of the ambipolar characteristics increases with increasing doping level of the n-Si while the p-branch current decreases. The SWNT band gap has the same influence on the p-branch current at a positive Vd and n-type characteristics at negative Vd. The lower the SWNT band gap, the higher the current. However, it has no impact on the n-branch current in the ambipolar characteristics. Thick oxide is found to significantly degrade the current and the subthreshold slope of the CNTFETs.

In this paper, we report the effect of Ga+ ion irradiation on anomalous Hall effect (AHE) and longitudinal resistivity in [Co(3 Å)/Pd(5 Å)]80 multilayer and Co42Pd58 alloy. 4- and 2-fold increases in anomalous Hall resistivity in the Co/Pd multilayer and CoPd alloy have been observed after irradiations at doses of and , respectively. Skew scattering and side jump contributions to AHE have been analyzed based on the scaling relationship . For the Co/Pd multilayer, AHE is mainly affected by ion irradiation-induced interface diffusion and defects. For the CoPd alloy, the increase in doses above induces a sign change in skew scattering, followed by the skew scattering contribution to AHE overwhelming the side jump contribution, this phenomenon should be attributed to irradiation-induced defects and modifications in chemical ordering.

Single-walled carbon nanotubes have been integrated into silicon for use in vertical carbon nanotube field-effect transistors (CNTFETs). A unique feature of these devices is that a silicon substrate and a metal contact are used as the source and drain for the vertical transistors, respectively. These CNTFETs show very different characteristics from those fabricated with two metal contacts. Surprisingly, the transfer characteristics of the vertical CNTFETs can be either ambipolar or unipolar (p-type or n-type) depending on the sign of the drain voltage. Furthermore, the p-type/n-type character of the devices is defined by the doping type of the silicon substrate used in the fabrication process. A semiclassical model is used to simulate the performance of these CNTFETs by taking the conductance change of the Si contact under the gate voltage into consideration. The calculation results are consistent with the experimental observations.

Extraordinary optical transmission (EOT) through arrays of gold nanoholes was studied with light across the visible to the near-infrared spectrum. The EOT effect was found to be improved by bridging pairs of nanoholes due to the concentration of the electromagnetic field in the slit between the holes. The geometrical shape and separation of the holes in these pairs of nanoholes affected the intensity of the transmission and the wavelength of resonance. Changing the geometrical shapes of these nanohole pairs from triangles to circles to squares leads to increased transmission intensity as well as red-shifting resonance wavelengths. The performance of bridged nanohole pairs as a plasmonic sensor was investigated. The bridged nanohole pairs were able to distinguish methanol, olive oil and microscope immersion oil for the different surface plasmon resonance in transmission spectra. Numerical simulation results were in agreement with experimental observations.

In this paper, we report anomalous Hall effect (AHE) correlated with the magnetoresistance behavior in [Co/Pd1−xAgx]n multilayers. For the multilayers with n = 6, the increase in Ag content from x = 0 to 0.52 induces the change in AHE sign from negative surface scattering-dominated AHE to positive interface scattering-dominated AHE, which is accompanied with the transition from anisotropy magnetoresistance (AMR) dominated transport to giant magnetoresistance (GMR) dominated transport. For n = 80, scaling analysis with Rs∝ρxxγ yields γ ∼ 3.44 for x = 0.52 which presents GMR-type transport, in contrast to γ ∼ 5.7 for x = 0 which presents AMR-type transport.

Vertically aligned carbon nanotube field-effect transistors (CNTFETs) have been experimentally demonstrated (J. Li et al., Carbon, 2012, 50, 4628-4632). The source and drain contact heights in vertical CNTFETs could be much higher than in flat CNTFETs if the fabrication process is not optimized. To understand the impact of contact height on transistor performance, we use a semi-classical method to calculate the characteristics of CNTFETs with different contact heights. The results show that the drain current decreases with increasing contact height and saturates at a value governed by the thickness of the oxide. The current reduction caused by the increased contact height becomes more significant when the gate oxide is thicker. The higher the drain voltage, the larger the current reduction. It becomes even worse when the band gap of the carbon nanotube is larger. The current can differ by a factor of more than five between the CNTEFTs with low and high contact heights when the oxide thickness is 50 nm. In addition, the influence of the contact height is limited by the channel length. The contact height plays a minor role when the channel length is less than 100 nm.

The growth of TiO2 films by plasma enhanced atomic layer deposition using Star-Ti as a precursor has been systematically studied. The conversion from amorphous to crystalline TiO2 was observed either during high temperature growth or annealing process of the films. The refractive index and bandgap of TiO2 films changed with the growth and annealing temperatures. The optimization of the annealing conditions for TiO2 films was also done by morphology and density studies.

The coupling between dielectric polarization and strain gradient, known as flexoelectricity, becomes significantly large on the micro- and nanoscale. Here, it is shown that giant flexoelectric polarization can reverse remnant ferroelectric polarization in a bent Pb(Zr0.52Ti0.48)O3 (PZT) diaphragm fabricated by micromachining. The polarization induced by the strain gradient and the switching behaviors of the polarization in response to an external electric field are investigated by observing the electromechanical coupling of the diaphragm. The method allows determination of the absolute zero polarization state in a PZT film, which is impossible using other existing methods. Based on the observation of the absolute zero polarization state and the assumption that bending of the diaphragm is the only source of the self-polarization, the upper bound of flexoelectric coefficient of PZT film is calculated to be as large as 2.0 x 10-4 C m-1. The strain gradient induced by bending the diaphragm is measured to be on the order of 102 m-1, three orders of magnitude larger than that obtained in the bulk material. Because of this large strain gradient, the estimated giant flexoelectric polarization in the bent diaphragm is on the same order of magnitude as the normal remnant ferroelectric polarization of PZT film.

p-Type nanocrystal NiO-based thin-film transistors (TFTs) are fabricated by simply oxidizing thin Ni films at temperatures as low as 400 °C. The highest field-effect mobility in a linear region and the current on-off ratio are found to be 5.2 cm(2) V(-1) s(-1) and 2.2 × 10(3), respectively. X-ray diffraction, transmission electron microscopy and electrical performances of the TFTs with "top contact" and "bottom contact" channels suggest that the upper parts of the Ni films are clearly oxidized. In contrast, the lower parts in contact with the gate dielectric are partially oxidized to form a quasi-discontinuous Ni layer, which does not fully shield the gate electric field, but still conduct the source and drain current. This simple method for producing p-type TFTs may be promising for the next-generation oxide-based electronic applications.

Vertically aligned carbon nanotube field-effect transistors (CNTFETs) have been developed using pure semiconducting carbon nanotubes. The source and drain were vertically stacked, separated by a dielectric, and the carbon nanotubes were placed on the sidewall of the stack to bridge the source and drain. Both the effective gate dielectric and gate electrode were normal to the substrate surface. The channel length is determined by the dielectric thickness between source and drain electrodes, making it easier to fabricate sub-micrometer transistors without using time-consuming electron beam lithography. The transistor area is much smaller than the planar CNTFET due to the vertical arrangement of source and drain and the reduced channel area.

The diode characteristics of carbon nanotube field-effect transistors (CNTFETs) with symmetric source and drain contacts have been experimentally found at zero gate voltage (Li J. et al., Appl. Phys. Lett., 92 (2008) 133111). We calculate this characteristic using a semiclassical method based on Schottky barrier transistor mechanism. The influences of metal work function, the diameter of the carbon nanotubes and the dielectric thickness on the rectification behavior have been studied. The calculation results show that the metal with a higher work function results in a better diode characteristics for a p-type CNTFET. For single-walled carbon nanotubes (SWNTs) with different band gaps, both forward current and reverse current increase with decreasing band gap, but the ratio of forward current to reverse current decreases with decreasing band gap. This result is well consistent with the experimental observations reported previously. The simulation of the dielectric thickness effect indicates that the thinner the dielectric layer, the better the rectification behavior. The CNTFETs without a bottom gate could not show the diode characteristics, which is consistent with the reported experimental observation.