Jinghua Yin

Gas-sens characteristics research of Al/CuPc/Cu Schottky diode

In this paper, evidence is provided that an organic Al/CuPc/Cu Shottky diode can be used as a novel gas sensor. This device is simple manufacturing process, lower costs, and shows good Schottky characteristics. Its structure includes three layers that are Al/CuPc/Cu. The sensitive feature of the device is characterized, through researching the change of electric properties in NO2 gas. The results of the study indicate that the current of device increased obviously along with the 10 ppm NO2 gas is accessed to. The potential barrier height in air and NO2 gas is calculated and compared. The results the potential barrier height of CuPc/Al reduced by 60 meV.

Analysis of the current transport mechanism of copper phthalocyanine Organic Static Induction Transistor

According to the test results of current-voltage characteristics, the current transport mechanism of Organic Static Induction Transistor (OSIT) using copper phthalocyanine (CuPc) as active layer is investigated. The transport mechanism of small current region and especially medium-large current region are all analyzed. Depending on in-depth theory analysis of experiment data about current-voltage characteristics, the current-voltage characteristic of OSIT exhibits exponential relationship in small current region. However, the current-voltage characteristic in medium-large current region is governed by with exponential trap distribution.

Device characteristics of vertical organic photoelectric transistor

Vertical organic photoelectric transistors (OPTs) with copper phthalocyanine (CuPc) as active layers have been fabricated. The structure of OPTs fabricated consists of five layers of Cu/CuPc/Al/CuPc/ indium tin oxide (ITO). Compared with traditional organic field effect transistor (OFETs), the structure of vertical conductive channel in OPTs is advanced to static characteristics with high working current value, low operation voltage and large switching current ratio. The static current-voltage output characteristics of OPTs in 700 nm light and in dark are observed. It can be seen that emitter-collector current (Iec) increases steadily with the increase of emitter-collector voltage (Vec). But Iec decreases with the increase o f base voltage (Vb), and that is the increase of Schottky barrier in base region. The operation current in 700 nm light is larger than the one in dark. The switching current ratio is 14.5.

Laminated structure of organic thin-film transistors preparation and gas sensing characteristics

Using the vacuum deposition method and the organic semiconductor copper phthalocyanine make of the structure of Au (Emitte)/CuPc/Al (Base)/CuPc/Au (Collector) the five-layer laminate structure organic transistor sensor. Specially appointed gases such as O2, NO2 will occur oxidation-reduction reduction when they were absorbed by the emitting regions organic thin film of organic transistor sensors, which equals to the doping effect of donor or acceptor, caused the change of carrier in organic film. To increase or decrease the carrier emitted by the source, the tunneling CuPc/Al/ CuPc double Schottky Barrier[10] gate region is formed operating current and changed. According to measuring the current change of organic transistor sensor to determined a specific gas.

Photoelectric characteristics of vertical structure organic phthalocyanine thin film transistor

In this paper, we have fabricated two types vertical structure organic thin film transistors (VOTFT) by vacuum evaporation and magnetron sputtering, the semiconductor material are copper phthalocyanine (CuPc) and lead phthalocyanine (PbPc) which have good photosensitive properties. CuPc used in this work thermally evaporated at the temperature of 400 °C, and PbPc was 330°C. The pressure were about 6.0×10-4 pa. Excitons will be generated after the optical signal irradiating into phthalocyanine, then transform into photocurrent under the built-in electric field formed by the Schottky contact. This makes the output current multiplication. The results show that the I-V characteristics of transistor are unsaturated. When CuPc transistor Vec=3 V, the ratio of white light and dark current is in the range of 2.9-6.4. The photocurrent IL=0.122 μA in white light, which is the 2.227 times of base current. The optical magnification of the device is 98.65.

The fabrication and operating mechanism analysis of copper-phthalocyanine organic thin film transistor

In order to make the operating characteristics of OFET device better, we used CuPc to fabricate organic thin film transistor with five layers structure of Au/ CuPc / Al / CuPc /Au with vertical conductive channel. Tested basic operating characteristics and analyzed relation between device structure and operating characteristics of it. The experimental results showed that drive voltage was low and i-v characteristics was unsaturated. Grid voltage has great control effect on operating characteristics of organic static induction transistor. Therefore, we can improving the driving voltage and switching characteristics of organic transistor by reasonable design the device structure to form vertical conductive channel.

Preparation and operation characteristics of nano-scale channel length vertical structure Zinc Oxide Thin Film Transistor

At room temperature, using with substrate of quartz glass, ZnO as active layer, we designed and prepared Zinc Oxide Thin Film Transistor with the structure of Ag/ZnO/Al/ZnO/Ag. The device shows the advantage of large operation electric current, low operate voltage and high charge carriers mobility and so on. When the device works, the drain could achieve at 9.15 mA, the threshold voltage Vth is only about 1.35 V, while the gate voltage VGS is 0.2 V, VDS is 3 V. The channel length is at only nano-scale.

The fabrication and UV photosensitive characteristics of Al/ZnO/Ag Schottky barrier diode

In this paper, n-type ZnO thin film was grown on single crystal Si ( 111 ) substrates by RF magnetron sputtering and high temperature annealing in vacuum. X-ray diffraction(XRD) and scanning electron microscope(SEM) were used to investigate film qulity and the structural performance. The results show that ZnO thin film is well c-axis oriented and the surface of ZnO is very clean and smooth. In the same conditions of depositing ZnO thin film, a vertical structure of Al/ZnO/Ag Schottky barrier diode detctor was designed and fabricated on the quartz glass substrate. The characteristics of dark-and photo-current of the Schottky UV photodetector was investigated. The results of testing at room temperature indicate that there is a good Schottky behavior between Ag and ZnO, the effective barrier height was determined to be 0.60 and 0.53eV by current-voltage and capacitance-voltage measurements respectively. The ideality factor was found to be 12.6, theoretical calculation of the space charge density was 3.1×1016 cm-3. At a bias of 3V, dark current was 24.19mA without illumination. Under illumination using monochromatic light with a wavelength of 365 nm, photogenerated current arrived at 3.28mA, at a bias of 3V, suggest that Al/ZnO/Ag UV photodetector has a significantly light response characteristics.