Light source for comfortable lighting and trapping pests in tea gardens based on solar-like lighting.

A large amount of tea is produced every year. Tea is often harmed by pests during the cultivation process, causing great economic damage. In this paper, we simulated a kind of light source for comfortable lighting and trapping pests based on solar-like lighting. We investigated three combinations of white LEDs and monochromatic LEDs for solar-like trapping light. The optimal combination of white LEDs and monochromatic LEDs was determined by the production cost and the spectral phototaxis ratio. We used TracePro for the trapping light mixing design. The results show that the combination of the cold white LED and six kinds of monochromatic LEDs is the best for trapping pests. A light source for comfortable lighting and trapping pests based on solar-like lighting with the color temperature of 7285 k, color coordinates of (0.3052, 0.3031), and color rendering index of 70 is obtained. The trapping light can not only be used as functional lighting but can also be applied to reduce the use of pesticides and improve the quality of tea.

Solar spectrum matching with white OLED and monochromatic LEDs.

In this paper, the solar spectrum matching in the visible range of 380-780 nm with white organic light-emitting diode (OLED) and monochromatic light-emitting diodes (LEDs) is investigated. The correlation index (R2) is used to evaluate the difference between the matching spectrum and the solar spectrum. The optimal combination is obtained by the least squares method. We also perform subtraction experiments to find the optimal combination. We utilize a common white OLED device design and just change the species of monochromatic LEDs used. We report and evaluate different degrees of matching effects. The results show that the correlation index of the best combination can reach 94.09% with white OLED and 36 monochromatic LEDs. We define three levels of performance as an evaluation system in accordance with the matching effect. The level is excellent with an R2 above 90.14%. The good level is from 86.65% to 58.28%. From 42.08% to 33.06% is the reasonable level. Compared with other methods, using white OLED combined with monochromatic LEDs achieves the best solar spectrum matching effect. The results can be applied to different requirements of engineering practice.

Synthesis and electrical properties of ZnO nanowires.

Vertically aligned ZnO nanowires were synthesized on the p(+) silicon chip by modifying the CVD process with a vapor trapping design. Scanning electron microscopy was used to investigate the morphology of as-obtained nanowires. X-ray diffraction showed that the obtained nanowires were ZnO crystalline. The rectifying characteristics of the p-n heterojunction composed of ZnO nanowires and a p(+) silicon chip were observed. The positive turn-on voltage was 0.5V and the reverse saturation current was 0.01mA. These vertically aligned ZnO nanowires showed a low field emission threshold of 4V/microm at a current density of 0.1microA/cm(2). The dependence of emission current density on the electric field followed Fowler-Nordheim relationship.

Morphology investigation of Ag(TCNQ) synthesized by the vapor-transport reaction method.

Ag(TCNQ) nanostructures with wire-, belt- and flower-like morphologies have been prepared on Si wafers by a vapor-transport reaction between silver and TCNQ without additional catalyst. The morphologies were characterized by SEM and optical microscopy. The composition of nanowires was tested by Raman spectroscopy. The growth mechanism of different morphologies based on the VS mechanism is emphasized.

Scanning electron microscopy investigation of Cu-TCNQ micro/nanostructures synthesized via vapor-induced reaction method.

Micro/nanostructures based on the metal-organic complex Cu-TCNQ were successfully synthesized by a novel method: vapor-induced reaction. Scanning electron microscopy was used to investigate the morphology on the three different parts of the substrate: the hot reaction area, a transitional reaction area and an induced reaction area. The results show that the morphology of the as-grown structures evolves from microstructures to nanostructures. The formation mechanism of these different structures may be understood from electrochemical principles and the decreasing concentration of TCNQ.

Microscopy investigation of Ag-TCNQ micro/nanostructures synthesized via two solution routes.

The micro/nanostructures of metal-organic complex Ag-TCNQ were successfully synthesized by the reaction between Ag film and TCNQ dissolved in acetonitrile via two solution routes, i.e. immerging and dipping reaction. X-ray diffraction confirmed that the obtained Ag-TCNQ micro/nanostructures were crystalline. The morphology of the as-grown structures varied from straight nanowires and microtubes to complex fractals and dendrites. The growth mechanism of the mainly dendrites may be considered within the framework of DLA model.