This project mainly develops the solid-state lighting sources for researching on plant growth. Regarding to the development of solid-state light sources, our laboratory has been researched for many years, and the technology has continuously pursued innovation and breakthroughs. In recent years, the solid-state lighting sources have also begun to develop toward deep ultraviolet wavelength region. Thus, it is in line with this trend and application.
Regarding UV LED (ultraviolet light emitting diode), the UV LED with 385 nm has been developed in our laboratory. When the operating current is 350 mA, the Vf of the 385 nm UV-LED / copper substrate is about 3.6 V, and its light output power is 379 mW. This result shows that the vertical LED process and high heat dissipation copper substrate can improve the output power of 385 nm UV-LED. We combined the UV-LED with the LED module to prepare a full-spectrum LED module and applied it to the field of plant light. However, we used two different light modules and chose lavender tincture for experiments. After a month, it was found that the growth height of lavender under the illumination of warm white LED modules was 3 cm. Using the LED full spectrum module (15 red + 7 blue + 4 white + 1 IR + 1 UV), the growth height was 8 cm. This result indicates that the LED full-spectrum module has the fastest growth rate, leading to achieve the saving energy.
In academic aspects, we focus on the development and optimization of deep ultraviolet light emitting diodes (UVC-LEDs). DUV-LEDs with four kinds of p-side electrode design (denoted as 3 fingers-LED, 6 fingers-LED, 9 fingers-LED, and 12 fingers-LED) were fabricated, and the conventional-LED was prepared as a contrasted sample. Finally, the flip-chip light-emitting diodes with 9- and 12-finger electrodes were further fabricated to investigate the device characteristics. At an injection current of 20 mA, the flip-chip device possessed 139%-improvements in the output power, as compared with those of 9 fingers-LED.
In industry-academia cooperation, Prof. Wuu and EPILEDS Co., Ltd. have an industry-academia cooperation plan, which is mainly aimed at the development of micro LED components. This plan has transferred one case including five patents.


Figure. Research Acheivements(Subproject 9)

Figure. The 1ST International Symposium on Precision Engineering(ISPE 2020) & The 2nd International Symposium on Engineering and Technology (ISET 2020)