SMD-type 660 nm wavelength semiconductor laser diode device is fabricated using silicon resin molding technology and fabricated a BT resin printed circuit board. BT resin electrode structure printed circuit boards with soldering electrode pads and through holes for heat dissipation were fabricated. The SMD process is an injection molding technique in which the chip is molded from silicon material and then cut by a dicing process to complete the beam emission surface. The fabricated SMD-type semiconductor laser diode exhibits a good near-field beam pattern with no scattering/dispersion caused by the printed circuit board or silicon molding in the emitted laser beam, or reflections around the chip. It was also confirmed that the heat generated at 20 mA operation has good heat dissipation characteristics through the through-hole heat dissipation structure.

Citations

• Mitigating Contact‐Constricted Thermal Bottlenecks by Magnetically Programmable hBN Bridge Fillers in Al2O3/Epoxy Composites
  Yeonwook Jeong, Sabina Ghorsaine, Chan‐Jae Lee, In Kim, Mooho Lee, Hyejeong Lee, Ginam Kim, Jong‐Woong Kim
  Small.2026;[Epub]     CrossRef

The amount of electric power for photovoltaic power generation depends on the location of the power plant and the direction of solar cell. The solar cell controls the generation of solar power plants. Therefore, the structure of solar cell, manufacturing method, and optic technology were factors contributing to increased solar cell efficiency; however, the technical limit has been reached. Herein, we propose a new method to increase the solar cell efficiency using a wavelength conversion technology that converts ultraviolet and infrared rays, which are not effectively used in solar cells, into effective wavelength of solar cell. We used fluoride Na(Ca)YF₄ phosphor for wavelength conversion. Then, a wavelength-conversion fluorescent paste, prepared using an organic-silicon binder, was used to prepare a film that was applied to Si solar cells. It was confirmed that conversion efficiency improved by 5% or more.

In this research, we focused on the improvement of cy3 dye’s characteristics for LCD color filter. Solubility and thermal stability are main characteristics of dyes for LCD color filter. We performed experiment to change counter cation of cy3 dyes with alkoxy substituent for these purposes. These cy3 dyes (1b∼5b) were prepared through the synthetic procedure of three steps. The synthesized new cy3 dyes were charaterized by using NMR, FT-IR, UV/Vis spectroscopy, and TGA. These cy3 dyes showed purple color and maximum absorption wavelength (λmax) in the range of 578∼590 nm in UV/Vis spectrum. We confirmed that solubility and thermal stability of cy3 dyes were dependent on the structure of counter cation. Cy3 dyes with alkoxy substituent have good solubility in organic solvents such as dichloromethane, methanol, and acetone. Especially, Cy3 dye with 4-nitrobenzyl counter cation (5b) gave excellent solubility characteristics.

In this research, we focused on the development of cy3 dye with high thermal stability and good solubility for LCD color filter. Cy3 dyes were prepared through the synthetic procedure of two steps. The synthesized cy3 dyes were characterized by using NMR, FT-IR, UV/Vis spectroscopy, and TGA. These cy3 dyes showed maximum absorption wave length (λmax) in the range of 549∼555 nm in UV/Vis spectrum. And we confirmed that solubility characteristics and thermal stability of cy3 dyes were dependent on the structure of counter cation. Cy3 dyes with methyl counter cation and ethyl counter cation have good solubility in organic solvents such as chloroform, ethanol, and PGME. Moreover, Cy3 dye with ethyl counter cation gave excellent thermal stability in TGA thermograms. And Cy3 dye with ethyl counter cation showed good result in photoresist film test.

The artificial light sources for growth of plant are usually high-pressure sodium lamp, metal haloids lamp, and fluorescent light; however, these light sources have relatively weaker Red and Blue lights that are necessary for growth of plants. Especially the effect of Photosynthetic Photon Flux Density (PPFD) is pointed out as the weakness. Meanwhile, LED light source can be selected by specific wavelength to greatly improve the effect of PPFD. In this regard, this paper aims to investigate the promotion of plant growth by measuring photosynthetic photon flux density (hereafter referred to as PPFD) according to changes in light quality of the LED light sources. Towards this end, LED light sources for plant growth were produced with 4 kinds of mono-chromatic lights and 6 kinds of combined lights by mixing red, blue, green and white lights. A comparative analysis was conducted to investigate the effects of optical properties and PPFD on plants (green leaf lettuce) using the produced light sources. The results monochromatic light has fastest growth rate, but plant growth conditions have poor. This being so, mixed light is suitable for the green leaf lettuce.

Citations

• Biodiversity in CEA: lighting strategies for enhanced contents of phytochemicals and nutraceuticals in plants
  G. Samuolienė, K. Laužikė, G. Kudirka, R. Sutulienė, I. Gudžinskaitė, A. Viršilė
  Acta Horticulturae.2024; (1391): 239.     CrossRef

Citations

• Quantitative Analysis of Charge Distribution in Bi-Emissive layer White Organic Light-Emitting Diodes with Two Fluorescent Dopants
  Ji Young Kim, Woo Young Kim, Kok Wai Cheah
  Scientific Reports.2018;[Epub]     CrossRef
• Electrical and Optical Properties of Organic Light Emission Devices using Selective Doping in a Single Host
  Yu Seok Seo, Dae Gyu Moon
  Journal of Korean Institute of Electrical and Electronic Materials Engineers.2010; 23(2): 124.     CrossRef
• Anisotropic Diffusion based on Directions of Gradient
  Hye-Suk Kim, Gi-Hong Kim, Hyo-Sun Yoon, Guee-Sang Lee
  The Journal of the Korea Contents Association.2008; 8(11): 1.     CrossRef
• Influence of Fluorescent Dye Doping on Efficiency of Red Organic Light-emitting Diodes
  Jeong-Gu Lee, Kee-Joe Lim
  The Journal of the Korea Contents Association.2008; 8(11): 18.     CrossRef