Advanced Materials Research Vol. 981

Abstract: CdS-capped CdSe nanocrystals (NCs) which show high luminescence quantum yield are synthesized without any Poisonous Materials in aqueous solution. The synthesis in an aqueous medium without any poisonous materials is attached importance to. The absorption spectroscopy and photoluminescence spectroscopy are employed to analyze the NCs. It takes 78s that the intensity decreases to the half for bare CdSe NCs, but 442s for CdSe/CdS core/shell NCs. The photo stability of CdSe NCs under 325nm laser irradiation is enhanced greatly after CdS overcoating.

Abstract: Aimed at the professional and printable materials, the researchers involved in higher payments, a new design scheme of utilizing MMA for 3D printing has been put forward based on its proper characters. The ideas and experiment frameworks are demonstrated, as well as the challenges are discussed.

Abstract: In high voltage direct current (HVDC) cable accessories, there is a large difference of conductivity between crosses linked polyethylene (XLPE) and liquid silicone rubber (LSR), especially considering the presence of temperature gradient and the changing of operating temperature. In this paper, nano silicon carbide (SiC) was adopted to prepare five kinds of nanocomposites with filler fractions of 1%, 2%, 3%, 4% and 5%, respectively. The conductivity and DC breakdown strength of SiC/LSR nanocomposites were measured under different temperatures. The results show that the nano SiC doping does not has the great influence on LSR DC breakdown strength, and the nano SiC doping can improve the conductivity of LSR effectively, which can realize the conductivity matching between the LSR and XLPE to homogenize the electric field distribution in cable accessory.

Abstract: High-pressure abrasive water jet cutting is a cold and non-traditional method, with many advantage which the traditional processing do not have.The traditional method of cutting marble have rough sections, poor dimensional accuracy, large seam, high tool cost and the processing efficiency is low. Can be considered high-pressure abrasive water jet cutting to improve its traditional cutting defects. This article explores the use of the pre-mixed abrasive water jet cutting in the marble, and its comparison with traditional methods, highlighting the advantages which the pre-mixed abrasive water jet cutting in the marble.

Abstract: Thin-film diode structure is MgAl/PbPc/Cu if lead phthalocyanine is taken as organic semiconductor gas-sensing material with methods such as vacuum thermal evaporation or magnetron sputtering. Use Keithley 4200 semiconductor instrument and Gas-sensing measurement system to analyze gas-sensing characteristic of Schottky diode device, the sensitive degree of NO₂ with different density can be compared through theoretical analysis of measured current and voltage data. The measurement result shows: when the device is placed in 10ppm NO₂ environment, after 74 minutes, forward current is decreased by 65 times, the corresponding MgAl/PbPc Schottky barrier height rises about 20meV. Reversed current of the device is 4 times larger because the increase of minority carrier electron number in PbPc thin-film is being absorbed by NO₂.

Abstract: Organic transistors consist of a vertical type are promising due to their shorter channel length. We have fabricated a vertical structure thin film phototransistor: ITO/CuPc/Al/CuPc/Cu. Detected this device and then the results show that the I-V properties of the transistors exhibit unsaturated characteristics and photosensitive characteristics. When V_ec=3V, amplification factor of the device without light is 16.5 and the 625nm light amplification factor is 266.2.

Abstract: We have fabricated Au/CuPc/Al/CuPc/Au organic thin film transistor (OTFTs) using vacuum deposition with CuPc thin films of stable chemical property and semi conductive Al gate thin film electrode. The static and dynamic characteristics were tested at room temperature. The test results show that the switching speed of the OTFT is t_on=2.68ms, t_off= 1.32ms, amplification bandwidth is 400Hz, and the cutoff frequency f_c=400Hz when inputting 100Hz small square wave signal. Our OTFT has submicron conductive channel, shows operation characteristics of high frequency, high speed and high current density. Good static and dynamic characteristics of OTFT can be obtained by controlling appropriate Al gate film thickness and CuPc film thickness.

Abstract: Using radio frequency magnetron sputtering deposition deposit ZnO films on SiO₂ glass, and prepare vertical structure ZnO-based thin film transistor. By means of measurement, obtain the static output characteristics, the output current can achieve the order of milliampere, get the transfer characteristics of ZnO TFTs; transconductance which get the largest value g_m=0.0061S when source-drain voltage V_DS=3V, source-gate V_GS=0.4V; output resistance and voltage amplification coefficient, the smallest voltage amplification factor is μ=1.16056,still have voltage amplification effect.

Abstract: The organic photoelectric transistors using the vacuum evaporation and sputtering process are prepared in this paper. The Cu/CuPc/Al/CuPc/ITO layer based on vertical structure is grown through a CuPc active layer. The CuPc has excellent photosensitivity and it is easy to be fabricated into Short-Channel device with vertical structure. It is shown that I-V characteristics of organic photoelectric transistors are unsaturated. In this experiment the light source is the Bromine-tungsten lamp in the range of 300nm to 800nm. When the light source irradiates the device with V_ec=2V, the operating current is 0.155μA which has been increased to 2.3-3.6 times as compared with the dark state. Therefore, the amplification coefficient of output current I_ec is increasing in irradiation with smaller base voltage. As a result, the current amplification coefficient β is 5.25 and 2.14 with illumination and without illumination respectively.

Abstract: The objective of this study is to investigate appropriate configuration used for micro direct methanol fuel cells (DMFCs). We designed grid and spiral flow fields of electrode plate and simulated with ANSYS. Using silicon-based micro–electro–mechanical systems (MEMS) technology to fabricate the DMFCs with different flow fields and tested at room temperature. Grid flow field can effectively improve methanol mass transport performance and exhibit higher cell efficiency than spiral flow field, demonstrating 13 mAcm-2 and 3.9 mAcm-2 in peak current density respectively and the peak difference of power density is nearly an order of magnitude. We tested Cell performance in different concentration methanol and it shows the best performance in concentration 2M.