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Agriculture is an important component of national economy in China, and agricultural production is also an important source of greenhouse gas emission. Based on the methods of IPCC, this paper has improved the method with the researches of a large number of scholars. Then, according to the agricultural production data of interprovincial regions of China from 1996 to 2014, the CO2, CH4 and N2O emissions from agriculture were carefully estimated. Then, based on the theory of club convergence in the field of economics, the estimation results are normalized and further analyzed. The results showed that the total CO2 emission has increased from 143.10 Tg in 1996 to 210.67 Tg in 2014, with an average annual growth rate of 2.17%. The largest emission source is the coal for thermal power, accounting for 30% of total emission. The total CH4 emission fell from 23.44 Tg in 1996 to 20.99 Tg in 1997 and then showed a slight fluctuation tendency; the rice field is found to hold major position, accounting for 59% of total emission. The total N2O emission has increased from 337.5 Gg in 1996 to 405.3 Gg in 2014, with an average annual growth rate of 1.02%. The main emission source is fertilizer, accounting for 59% of total emission. The total agricultural greenhouse gas emission in China shows an upward trend, increases from 915.09 Tg CO2 Eq. in 1996 to 965.90 Tg CO2 Eq. in 2014, with an average annual growth rate of 0.3%. The fastest growing area is Heilongjiang, followed by Xinjiang.

We successfully prepared Ag quantum dots modified TiO2 microspheres by facile solvothermal and calcination method. The as-prepared Ag quantum dots/TiO2 microspheres were characterized by scanning electron microscope, transmission electron microscope, X-ray diffraction, X-ray photoelectron spectroscopy and UV-vis diffuse reflectance spectroscopy. The Ag quantum dots/TiO2 photocatalyst showed excellent visible light absorption and efficient photocatalytic activity for methyl orange degradation. And the sample with the molar ratio of 0.05 (Ag to Ti) showed the best visible light photocatalytic activity for methyl orange degradation, mainly because of the surface plasmon resonance (SPR) effects of Ag quantum dots to generate electron and hole pairs for enhanced visible light photocatalysis. Finally, possible visible light photocatalytic mechanism of Ag quantum dots/TiO2 microspheres for methyl orange degradation was proposed in detail.

With the panel data of 30 administrative regions in China, this paper first used mechanical power, thermal energy, chemistry, biodynamic energy as input index, gross output value of agriculture, forestry, animal husbandry and fishery value as output index, built the DEA model to analyze the agricultural total factor energy efficiency(TFEE) of each province from 1997 to 2014. By using the Malmquist index, the total factor productivity(TFP) is decomposed into the technology progress change(TPCH) and the technology efficiency change(TECH) from 1997 to 2014. The results show that the average agricultural total factor energy efficiency level in the eastern region is the highest, followed by the central region, the western region is the lowest. China’s agricultural TFP has the slow growth trend in the fluctuations, which was powered by TECH.

A heterostructured Ag3PO4/TiO2 film sample was synthesized using a facile method to improve the efficiency for the solar energy conversion of conventional TiO2 material and accelerate its applications. The preparation strategy of this study provides a simple way to fabricate photocatalytic film samples with relatively low cost. The microstructure and the photocatalytic properties of the as-prepared film samples were investigated in detail. The Ag3PO4/TiO2 film sample shows strong visible light absorption ability, together with high photocatalytic efficiency and activity for degradation of methyl orange. Furthermore, the inter-semiconductor hole-transfer mechanism leads to the enhanced visible-light driven activity for this kind of photocatalyst.

In this paper, gold (Au) nanocrystals based nonvolatile floating gate OFET memory devices with light assisted program are studied. Programmable memory characteristics were observed according to the programming/erasing operations and the memory window and on/off memory ratio were dramatically improved from 18 V, 102 to 63 V, 105 through light assisted program, respectively. Good reliability was confirmed by the data retention and endurances characteristics. Therefore, this method has potential applications in organic memory devices and integrated circuits.

There are two critical issues involved in voltages of organic thin-film transistors (OTFTs), i.e., high operating voltages Vop and random distributed threshold voltages VTH, which lead to high power consumption and unreliable logic function in organic integrated circuits, respectively. This paper demonstrates that both issues can be solved in a single OTFT device by using very thin insulator films. The operating voltages could be reduced to be less than 3 V, without lowering the mobility and the on/off ratio. Using light-enhanced bias stress effect, the threshold voltages can be tuned into the range of -4 to 4 V in OTFTs with SiO2 or Al2O3 as dielectric films, demonstrating that light-enhanced bias stress effect in OTFTs is independent of the dielectric material. The ΔVTH/Vop ratio is about 3, which is one of the largest threshold-voltage-shifting ratios. It is found that the threshold voltage shifting has a linear relationship with the bias voltage and the light illumination time. This tuning technology is a post fabrication and noninvasive method with negligible influence on the mobility and on/off current ratios.

Among the many possible device configurations for organic memory devices, organic field-effect transistor (OFET) memory is an emerging technology with the potential to realize lightweight, low-cost, flexible charge storage media. In this feature article, the recent progress in the classes of OFET-based memory, including floating gate OFET memory, polymer electret OFET memory, ferroelectric OFET memory and several other kinds of OFET memories with unique configurations, are introduced. Finally, the prospects and problems of OFETs memory are discussed.

In order to realize the micromation of position sensors, and extend the application area into micro scale, this paper designs a novel micro position sensor, Mace SAW (Surface Acoustic Wave) position sensor, which can be fabricated with MEMS technology. Its key components are IDTs (Interdigital Transducers) and reflective grooves. The structure and working principles of the sensor are introduced theoretically, and the manufacture process is then put forward.

Low voltage operating organic devices and circuits have been realized using atomic layer deposition deposited aluminum oxide thin film as dielectric layer. The dielectric film has per unit area capacitance of 165 nF/cm2 and leakage current of 1 nA/cm2 at 1 MV/cm. The devices and circuits use the small-molecule hydrocarbon pentacene as the active semiconductor material. Transistors, inverters, and ring oscillators with operating voltage lower than 5 V were obtained. The mobility of organic field-effect transistors was extracted to be 0.16 cm2/Vs in saturation range, the threshold voltage is 0.3 V, and the on/off current ratio is larger than 105. The gain of inverters is estimated to be 12 at −5 V supply voltage, and the propagation delay is 0.25 ms per stage in 5-stage ring oscillators.

Organic field-effect transistors (OFETs) have received significant research interest because of their promising applications in low cast, lager area, plastic circuits, and tremendous progress has been made in materials, device performance, OFETs based circuits in recent years. In this article we introduce the advances in organic semiconductor materials, OFETs based integrating techniques, and in particular highlight the recent progress. Finally, the prospects and problems of OFETs are discussed.

In this paper, the reproducible nonpolar resistive switching is demonstrated in devices with the sandwiched structure of Au/poly(3,4-ethylene-dioxythiophene): polystyrenesulfonate/Au for nonvolatile memory application. The switching between high resistance state (OFF-state) and low resistance state (ON-state) does not depend on the polarity of the applied voltage bias, which is different from both the WORM characteristics and the bipolar switching characteristics reported before. The resistive ratio between the ON- and OFF-state is on the order of 103 and increases with the device area decreasing. Both the ON- and OFF-state of the memory devices are stable, showing no significant degradation over 104 s under continuous readout testing. It is proposed that the reduction and oxidation of PEDOT: PSS film might be the switching mechanism.

Pentacene organic field effect transistors with a series of sub-micrometer channel have been fabricated and characterized. Source and drain metal electrodes was made by electron-beam lithography and lift-off process. Image reversal photo resist was used to make integrated mask to pattern the organic semiconductor film to reduce the off-state current. And thiol treatment was applied on gold electrodes to modify their surface energy and improve the charge carrier injection. All the devices can behavior as typical p-type transistor, and have obvious saturation. Using electrode and dielectric surface treatment, device performances have significant improvement. All of the performances, including mobility, threshold voltage and on/off current ratio will change with the channel length decreasing because of the low quality interface between the OSC and dielectrics.

We fabricated high performance organic field-effect transistors with novel hybrid electrode-semiconductor contact geometry. The HC OFETs contain both the top electrodes and the bottom electrodes in a single transistor simultaneously. The bottom electrodes induce an ordering CuPc film during the active layer depositing. Due to a high order CuPc layers and low total device resistance, as well as little charge effect below the top electrodes, OFETs with the hybrid contact geometry exhibit a higher performance. With convenience of the new structure, the contact resistance between the two traditional contact geometries was studied in one single transistor.

This paper reports on the application of a bilayer polymethylmethacrylate (PMMA)/ZrO2 dielectric in copper ph-thalocyanine (CuPc) organic field-effect transistors (OFETs). By depositing a PMMA layer on ZrO2, the leakage of the dielectric is reduced by one order of magnitude compared to single- layer ZrO2. A high-quality interface is obtained between the organic semiconductor and the combined insulators. By integrating the advantages of polymer and high-fe dielectrics, the device achieves both high mobility and low threshold voltage. The typical field-effect mobility, threshold voltage, on/off current ratio, and subthreshold slope of OFETs with bilayer dielectric are 5.6 times 10-2 cm2/V ldr s, 0.8 V, 1.2 times 103, and 2.1 V/dec, respectively. By using the bilayer dielectrics, the hysteresis observed in the devices with single-layer ZrO2 is no longer present.

Increasing the alignment of thin films, which leads to anisotropy, is an attractive way to improve the performance of organic devices. A highly controllable and reproducible method to fabricate organic field effect transistors with large anisotropic ratios was proposed in this paper. The surface of the dielectric layer was etched to form patterns through conventional semiconductor processing. Transistors having current direction perpendicular to or parallel to the direction of the patterns were fabricated and characterized. The mobilities of these two kinds of transistors are 0.016 and 0.001 cm 2 /Vs respectively, which means the anisotropic ratio is 16.

In this letter, high-performance organic phototransistors and photoswitches based on an ultraclosely π-stacked organic semiconductor, i.e., titanyl phthalocyanine, are fabricated. The p-type transistor exhibited high performance with a hole mobility of ~ 4. 5 cm2·V-1·s-1 and an on/off ratio higher than 3.1 × 107. Phototransistors exhibited high-photoresponse properties with a responsivity at 10.5 A/W and a photosensitivity up to 2.7 × 105. The high performance of the devices showed their potential application in optoelectronic organic integrated circuits.

A low-voltage multilevel organic thin-film memory device is proposed and demonstrated for nonvolatile data storage. Charge carrier density in the storage field was tuned up to four discrete levels in pentacene organic thin-film transistor with poly(methyl methacrylate)-modified Al2O3 film as the dielectric layer through light-assisted program procedures. Charges can be stored over 1 × 104 s at room temperature. The states can be clearly distinguished after 1 × 104 write-read cycles.

In this letter, an organic memory cell based on tris(8-hydroxyquinolinato)aluminum doped with gold nanoparticles is reported. The device can achieve good resistive switching properties, such as a high on/off current ratio of about 104, and good retention (4 h at 0.1 V). The device remains in either state even after the power has been turned off and shows a good stability under stress test. The current-voltage characteristics are comprehensively investigated, and a possible mechanism is proposed and well fitted with the experiment data. The results show that the organic memory devices have promising potentials for future flexible electronic systems.

For the first time, we present a surface potential-based compact model for a-IGZO TFTs based on multiple trapping-release theory and benchmark our work against device measurements. This model does not require time-consuming calculation. Meanwhile, we have developed the automatic parameter extraction program, which can extract the parameters rapidly and accurately. Moreover, the compact model is coded in Verilog-A, and implemented in a vendor CAD environment. This model provides physics-based consistent description of DC and AC device characteristics and enables accurate circuit-level performance prediction and RFID circuit design of a-IGZO TFTs.

In this letter, the effect of the interface on the electrical characteristics of a rectifier based on an organic diode with pentacene as the electroactive layer is studied. It was found that the on/off ratio had a strong correlation with the interface effect (i.e., the bottom electrode material). The rectification ratio was improved to 2 × 106 at 5 V by modifying the bottom electrode with copper tetracyanoquinodimethane. The ac rectification frequency exceeded 13.56 MHz, which is a main requirement for an organic radio-frequency identification application.

In this paper, low-cost rectifier based on an organic diode for use in organic radio frequency identification (RFID) tags is proposed. Pentacene is the electroactive layer, with 7,7,8,8-tetracyanoquinodimethane (TCNQ) modified low-cost copper (Cu) and aluminum (Al) as the Ohmic and Schottky contacts, respectively. Hole injection barrier between Cu and pentacene can be decreased by forming the self-assembled layers of Cu-TCNQ. The diode shows a high rectification ratio of approximately 2×106 at 5V and the organic diode based rectifier circuit generated a dc output voltage of approximately 2V at 13.56MHz, using an input ac signal with zero-to-peak voltage amplitude of 5 V. The results indicate that chemical modification of the low-cost electrodes could be an efficient way toward low-cost high performance organic electronics devices.

Currently, there exist in the construction of system of public financial management certain problems and inadequacies, which cannot meet the public sectors' demand for financial management and fiscal management. Under the supervision of the government and with support of relevant theory, efforts should be made to sort out the problems existed in the system of public financial management to establish a combined mechanism that consists of expenditure decision, budget management, process control management, financial supervision, and achievement evaluation and etc to promote the Public Financial Management System to be more scientific, standard and precise.

Under white-light irradiation, thin film transistors based on copper phthalocyanine (CuPc) exhibited obvious hysteresis effects when applying bi-directional sweeping gate voltage, the hysteresis window comes up to 32 V. This hysteresis effect is the result of those accumulated photogenerated carriers trapped in the interface, which proposed a feasible way to detect the state of the interface between organic functional materials and the dielectric layer.

The sections in this article are 1.1 Introduction 1.2 Lithography 1.2.1 Photolithography 1.2.1.1 Contact Printing 1.2.1.2 Proximity Printing 1.2.1.3 Projection Printing 1.2.1.4 Resolution Enhancement Techniques (RETs) 1.2.1.5 Optical Proximity Correction (OPC) 1.2.2 Electron Beam Lithography 1.2.3 X-Ray Lithography 1.2.4 Focused Ion Beam (FIB) Lithography 1.2.4.1 Direct-Write Milling 1.2.4.2 Dry Development FIB Lithography 1.3 Two-Dimensional Nanostructures: Thin-Film Deposition 1.3.1 Fundamentals of Film Growth 1.3.2 Physical Vapor Deposition (PVD) 1.3.2.1 Vacuum Evaporation 1.3.2.2 Molecular Beam Epitaxy (MBE) 1.3.2.3 Sputter Deposition 1.3.3 Chemical Vapor Deposition (CVD) 1.3.3.1 Reaction Kinetics 1.3.3.2 Variants of CVD Methods [98] 1.3.3.3 Advantages of CVD 1.3.4 Atomic Layer Deposition (ALD) 1.3.4.1 ALD Process 1.3.4.2 Types of ALD Reaction 1.3.4.3 Advantages and Disadvantages 1.4 Pattern Transfer 1.4.1 Etch 1.4.1.1 Wet Etching 1.4.1.2 Dry Etching 1.4.1.3 A Comparison of Wet and Plasma Etching 1.4.2 Lift-Off Processes Keywords: top-down; photolithography; two-dimensional nanostructure; film deposition; pattern transfer; lift-off

Low dimensional molecular crystals of Ni[TCNQ] 2 (H 2 O) 2 was controlled synthesized by water in large area. Based on the accurate control of the reaction, the nanorods assembled in bundle clusters The nanorods have an average radius at ∼450 nm, with the length at 5 micrometers.

By depositing a PMMA (poly(methyl methacrylate)) layer on top of an evaporated layer of ZrO2, the leakage has 4 orders of magnitude reducing compared with bare ZrO2 layer. Low roughness of PMMA/ZrO2 surface produces a high quality interface between the organic semiconductor and the combined insulator, thus the device has a significant improvement in performance. The typical field effect mobility, on/off current ratio, and sub-threshold slope of OFETs with bilayer dielectric are 5.6×10-2 cm2/Vs, 1.2×103, and 0.3 V/decade respectively. It is noticeable that the threshold voltage is only 0.1 V.

Carbon nanotube (CNT) bundle is a promising candidate for future on-chip interconnects and electro-thermal applications due to its superior electrical and thermal properties. A realistic CNT bundle is a mixture of single-wall/multi-wall CNTs due to the nature of bottom-up fabrication process. In order to utilize CNT bundle, its current density performance needs to be analyzed considering both types of CNTs. In this paper, compact current density models are introduced for CNTs and mixed CNT bundles considering the influence of diameter and other structural factors. The current density performance estimation based on these models match the recent measurement results. Considering realistic CNT densities and geometries, the mixed bundle shows various levels of improvement over the copper wire counterpart in terms of current density.

This work studied systemically the device characteristics when the OFETs' channels turn into hundreds of nm. Standard planar OFETs have been fabricated using electronic beam lithography. Copper phthalocyanine is used as the semiconductor materials. When reduce the L to about 300 nm will lead an abrupt degradation of device performance. The ratio of Ion/Ioff turns from several hundreds into couple of tens. And when change the L to about 100 nm, the mobility turns from 10−2 cm2/Vs into 10m5 cm2/Vs, and the threshold voltage turns from about 12 V into 36 V. These abrupt changes are due to the changes of interface between active layer and insulator layer caused by the reducing the L to close to the grain size.

In this work, a bilayer resist system with ZEP520 as the top layer and lift-off resist (LOR) as the bottom layer for lift-off process was investigated for the first time. The formation of undercut was studied as a critical step which makes lift-off process much more feasible in bilayer resist process. Using different dissolution rates of LOR layer, the length of undercut can be well controlled, providing reliable process. The top layer of ZEP520 is more efficient than other resists (PMMA etc.) for e-beam lithography, due to its high resolution and high sensitivity. Here, a set of process parameters have been optimized to fabricate Cr metal lines with a width of less than 70 nm. This bilayer lift-off resist system can be widely used in nano-fabrication for various nano-scale structures and devices.

Carbon nanotube (CNT) bundle is a promising candidate for future electrothermal applications due to its superior thermal properties. A realistic CNT bundle is a mixture of single-wall/multi-wall CNTs due to the nature of bottom-up fabrication process. In order to utilize CNT bundle, its thermal performance analysis needs to be carried out considering both types of CNTs. In this paper, accurate thermal conductance models are introduced for CNTs and mixed CNT bundles considering the influence of diameter and other structure factors. The thermal performance estimation based on these models match the recent measurement results. Considering realistic CNT densities and geometries, the mixed bundle shows 2-3 times improvement over the copper wire counterpart in terms of thermal conductance.

Copper phthalocyanine (CuPc) thin-film transistors (TFTs) have been fabricated using 400 nm polyimide (PI) cured at 250degC as gate dielectric. The root-mean square surface roughness of PI films is 30 Aring. An individual bottom gate, staggered structure was selected to study the device performance. The devices showed p-type electrical characteristics with field-effect mobility, threshold voltage and current on/off ratio values around 1.44 times 10-3 cm2V-1s-1, 1.1 V and 12, respectively.

We report on a micro-Raman investigation of inducing defects in mono-layer, bi-layer and tri-layer graphene by γ ray radiation. It is found that the radiation exposure results in two-dimensional (2D) and G band position evolution with the layer number increasing and D and D' bands rising, suggesting the presence of defects and related crystal lattice deformation in graphene. Bi-layer graphene is more stable than mono- and tri-layer graphene, indicating that the former is a better candidate in the application of radiation environments. Also, the DC electrical property of the mono-layer graphene device shows that the defects increase the carrier density.

In this paper, organic thin film transistors based on titanyl phthalocyanine were fabricated on octadecyltrichlorosilane (OTS) stripe modified Si/SiO2 substrates. The p-type transistor exhibited high performance with a hole mobility of ∼4.25 cm2V−1s−1 and an on/off ratio greater than 3.1 × 107 on 1 µm wide OTS stripe modified substrates. The charge transport anisotropy was observed in devices fabricated with channels parallel and perpendicular to the OTS stripes, indicating that the molecular orientation was optimized and arranged in a more ordered style. The high performance of the devices showed their potential for application in organic circuits.

Applying a bidirectional sweeping gate voltage, the white-light illuminated copper phthalocyanine thin-film transistors (CuPc-TFTs) show obvious hysteresis effect and the hysteresis window is 32 V. This effect is dominated by the additional carriers generated by photoirradiation. Although small hysteresis exists in CuPc-TFTs without illumination, light makes the hysteresis more obvious. Thus, CuPc-TFTs are promising to realize light detection and/or light memory in a single organic device for future low-cost, ultrahigh-density organic photoelectric integration.

An all-organic memory device based on a copper phthalocyanine (CuPc) thin-film transistor (TFT) using gold nanocrystals embedded in a polyimide gate dielectric is demonstrated. Both the gate dielectric and the active semiconductor layer are organic materials. Discrete gold nanocrystals are adopted as the charge storage medium. Under proper gate bias, gold nanocrystals are charged and discharged, resulting in the modulation of the channel conductance. Current–voltage (I–V) measurements at room temperature show the memory behaviour of the fabricated devices. The detailed programming and erasing operations are discussed. Low fabrication temperature and low cost are two benefits of the fabricated memory devices, which could provide a low-cost solution for the all organic circuits.

The electrical switching characteristics of eicosanoic acid (EA)/zirconium oxide (ZrO2) bilayer thin films are investigated in this letter. The devices have a sandwich structure of aluminum (Al)∕EA∕ZrO2∕gold (Au) and exhibit asymmetric electrical bistable behavior with a rectifying effect through resistive switching. Reversible and reproducible bistable switching properties were observed by applying certain voltages. The asymmetry and rectifying bistable behavior is proposed to result from the Schottky barrier that is present by reason of the ZrO2 layer. The rectifying effect can significantly improve misreading in matrix crossbar memory based on bistable two-terminal devices, paving a way for a practical crossbar molecular memory.

Carbon nanotube (CNT) bundle is a promising candidate for future electrothermal applications due to its superior thermal properties. A realistic CNT bundle is a mixture of single-wall/multi-wall CNTs due to the nature of bottom-up fabrication process. In order to utilise CNT bundle, its thermal performance analysis needs to be carried out considering both types of CNTs. In this paper, accurate thermal conductance models are introduced for CNTs and mixed CNT bundles considering the influence of diameter and other structure factors. The thermal performance estimation based on these models match the recent measurement results. Considering realistic CNT densities and geometries, the mixed bundle shows two to three times improvement over the copper wire counterpart in terms of thermal conductance.

This letter reports the synthesis of an organic molecule N,N′-bis (salicylidene)-1,6-hexanaphthenediamine (BSH) and the study of its electrical properties. Reversible electrical bistable behavior was observed both in BSH organic thin film on indium tin oxide substrate and in a crossbar device fabricated via standard integrated circuit processing with this thin film. The proton transfer model, induced by a bias higher than the switch threshold voltage, was employed to explain the electrical bistable phenomenon. This electrical bistability of BSH molecules is a key property for potential applications in organic nonvolatile memories and programable switches.

The carbon nanotube (CNT) bundle is a promising candidate for next-generation interconnect/via applications. A realistic CNT bundle is a mixture of single-wall and multi-wall CNTs and its performance analysis needs to consider both kinds of CNTs. The inductances of the mixed CNT bundles are estimated, which are in agreement with the recent experimental results. Impacts of different parameters such as tube density, tube distribution, metallic tube ratio and bundle dimensions are discussed, providing an important guideline to design and fabricate a CNT bundle with a desirable inductance performance.

Recent research has revealed that the overall effective mobility of organic field-effect transistors depends on the anisotropy film. To account for this behavior, a modified model is proposed based on the previous grain boundary trap model. In this model, the degeneration factor, which is related to the maximal misorientation angle of grains, is introduced to describe the difference between aligned and nonaligned organic films. More explicit definitions of effective grain length and grain boundary are given concerning this anisotropic phenomenon. The simulation results are consistent with experimental data for aligned pentacene and copper phthalocyanine (CuPc).