2006.10
About Instruments Today No. 154
LED Solid-State Lighting
"Solid-State Lighting Development Status, Prospect, Challenge and Opportunities in Taiwan" [ 下載 PDF ]
Schiu Sche
The prospect, challenge and critical issues toward solid-state lighting (SSL) opportunities have been reviewed for Taiwan LED lighting industry. The intellectual property is a vital issue that Taiwan LED industry, government-sponsored research organizations ITRI, as well as the domestic universities have to find a strategic approach jointly to settle it. Not just because Taiwan is over 90% dependent on imported energy sources, but also because of the Taiwan status as top supplier worldwide of high brightness LED, which forms the foundation of solid-state lighting. To access to the world market effectively, Mainland China is not only a tremendous market, but also a mutualbeneficial cooperation partner. Then, the market strength could be converted to a bargain power of IP and standardization of SSL. Finally a list of technical issues has been selected which could bring a breakthrough in the technology as well as the applications.
Introduction to LED Solid-State Lighting and the Associated Optical Simulation and Design [ 下載 PDF ]
Ching-Cherng Sun
In this paper, we first introduce the development of LED solid-state lighting and the most important issues in increasing light efficiency of GaN-based LED. Then, we propose three potential applications based on LED lighting, such as auto-/motor- forward lighting, LCTV backlighting, and lighting in project TV. Finally, we introduce a new optical modeling algorithm which was proposed by National Central University. Besides, we introduce the concept of mid-field in the model and demonstrate a design result.
Photonic Crystal Light-Emitting Diodes [ 下載 PDF ]
Jian-Jhong Chen, Yan-Kuin Su
Optical losses of light-emitting diodes (LEDs) include Fresnel loss and total internal reflection loss. These losses erode the luminous efficiency seriously. A couple of methods have been proposed to overcome the light extraction efficiency, but the improvement of these solutions is still limited. Photonic crystal LEDs have attracted many researchers' attentions for the higher extraction efficiency. Application of photonic crystals on LEDs should be a trend for the future. In this paper, we have described the theory and the fabrication techniques about photonic crystals. Finally, how to apply photonic crystals on LEDs is discussed, and the advantages/disadvantages of each method are compared.
An Introduction of SrSi2N2O2:Yb Phosphors for Light Emitting Diodes [ 下載 PDF ]
Ru-Shi Liu, Yu-Huan Liu
The first white LED, commercialized in 1996, is composed of a blue LED and a yellow phosphor layer, namely, yttrium aluminum garnet (YAG). The color rendering index (Ra) of the YAG-based LED is about 80, which is enough for general illumination. However, it is not suitable for certain medical applications and architectural lighting purposes due to the poor performance of red component in the spectra. Moreover, the YAG phosphor has the disadvantage of thermal quenching at high temperature. In this study, we concentrate on SrSi2N2O2:Yb phosphors among the oxynitride compounds, which are nontoxic and stable under high temperature. Besides, photoluminescence (PL) and the CIE chromaticity coordinates were obtained to show emission properties.
Applications of High Resolution Nuclear Magnetic Resonance Micro-Imaging in Materials and Biological Systems [ 下載 PDF ]
Shangwu Ding, Zhen Wu, Peter Po-Jen Chu, Ying-Ru Shi, Wen-Yan Liang, Kuo-Hsun Chiu, Michael Hin-Kiu Mok
This review presents some recent progress in the methodological development of magnetic resonance micro-imaging (µMRI) and its applications in materials science and biological systems. Exemplified with a number of representative systems which are highly valuable in industry and academically important, including electrode membranes of fuel cells, sesame seeds as well as hard bones and cartilages of marine fish, the extensive applications of microscopic MRI images with various weighting approaches to the investigations of micro-structures and dynamics including the developmental processes of plants are demonstrated. In addition, the latest trend in this field is introduced, such as diffusion tensor imaging, new generation contrast agents, sample spinning as well as image processing algorithms that help enhance sensitivity and resolution.
New Plasma Treatment for Semiconductor Waste PFC Gases [ 下載 PDF ]
Yung-Chih Chen, Shiaw-Huei Chen
Kyoto Protocol, which regulates and limits mainly the emission of six kinds of greenhouse gases (CO2, CH4, N2O, HFCs, PFCs, and SF6), came into effect on February 16, 2005 officially. Among these regulated greenhouse gases perfluorocompounds (PFCs), which were used commonly in aluminium and semiconductor manufacturing industries, are the artificial, most stable and effective greenhouse gases and are difficult to remove. Traditional tail gas abatement equipments of PFCs used by semiconductor factory were less effective, so a new and efficient removal equipment of PFCs is very anticipated and holds a great business opportunity in the future. In this paper a thermal plasma torch technique is introduced, high temperature plasma is generated and utilized to destruct PFCs of semiconductor waste gas directly, and the efficiency of abatement can be up to 99.9% for C2F6 and CF4, and the byproducts were mainly CO2 and HF which can be easily handled. Currently this technology had obtained patent and been transferred, a plasma local scrubber based on this had been assembled and evaluated in various semiconductor plants. For quality assurance, this equipment also had passed the test of PFC removal verification performed by the center of environment and safety of ITRI.
Introduction to Ion Beam Processing Technology (I) [ 下載 PDF ]
Han-Chang Pan, Chien-Ying Su, Chien-Nan Hsiao
A review of various ion beam assisted deposition (IAD) techniques of functional thin film is presented. The different kind of IAD techniques such as, sputtering and evaporation, chemical vapor deposition, reactive etching, and polymer surface modification are discussed. This is followed by a discussion of physical and chemical properties in use to explain ion-to-film interaction in the ion beam assisted process.
"The Basic Principle, Technology and Applications of Nano Positioning Sensor Utilizing Nematic Liquid Crystal" [ 下載 PDF ]
Ming Yen Lin
A new positioning sensor and controller by utilizing electro-optic effect of nematic liquid crystal, which achieves ±0.5 nm of resolution, ±20 nm of repeatability, 10 mm/s of velocity and low cost, has been successfully developed by a research team, lead by Prof. Katsumi Yoshino, at the Center for Advanced Science and Innovation in Osaka University. This new device can be easily integrated to actuators and linear servo motor and also satisfies nano positioning applications for robot, factory automation, bio-engineering and scientific instruments.
Prototyping of a Biomedical Compact Disc Inspection System [ 下載 PDF ]
Fu-Shin Lee, Jong-Zen Huang, Wen-Yuan Zheng, Shao-Chin Tseng
The object of this paper is to discuss the basic design approach for a bio optical compact disc (BioCD) system, which has drawn extensive attentions within the biomedical industries during last decade. The related researches are becoming more valued due to a BioCD typical system usually integrates an optical focusing platform operated by piezoelectric actuators, well-managed microchannels on the discs fabricated by semiconductor or micro-stamping manufacturing, an image processing mechanism for the collected fluorescence from the specimen reactions, and the highly developed optical disc driving mechanisms as well as the optic media coding technologies. In this paper, the basic principles of con-focal mechanisms and structure design of a BioCD system are stated first, and then followed with the inductions of a desktop as well as an embedded BioCD approaches. Essentially, both of introduced systems employ con-focal principles and piezoelectric actuators to design a three-group lens system, which is aimed to achieve fluorescence image amplification as well as optical slicing functions for the specimen. In the last, the collected slicing images of the specimen could be transmitted to an image processing mainframe, which is used to conduct certain pattern recognition and symptom identifications.
Wireless Sensor Networks for Monitoring Indoor Environment: An Application to Hospital Buildings [ 下載 PDF ]
Tzu Hsuan Lin, Shih-Lin Hung, Ren-Jang Wu, Yu-Ching Huang, Hsiang Ning Liu, Murthy Chavali
The total design and development of wireless gas sensor system using in situ UV photopolymerized conducting polypyrrole, as a sensing material was investigated for measuring volatile organic compounds like most common inhalation anesthetic agent, fluoromethyl 2,2,2,-trifluoro-1-(trifluoromethyl) ethyl ether, sevoflurane. This sensor shows promising application towards hospital surgical indoor environments especially in postoperative recovery phase. The conducting polypyrrole films were dip coated over a pair of interdigitated comb shaped gold electrodes that were previously screen printed on an alumina substrate, subsequently integrated with the system electronics. Results shown the response of the sensor is rapid with multifold change in resistance and was very stable. The response time T90 (T90 represents the time to 90% signal with the equilibrium signal) of 5.77% sevoflurane sensing curve is less than 60 second, and recovery time was also less than 60 second. The response to different vapors was also investigated, with vapors from alcohol and acetone.
