28 results on '"Chia-Fu Hsu"'
Search Results
2. Development of a highly efficient, strongly coupled organic light-emitting diode based on intracavity pumping architecture
- Author
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Tong Yu Lin, Cheng-Chung Lee, Cheng-Chung Jaing, Guo Sian Ciou, Chia Fu Hsu, Shun Yu Hong, Jui Fen Chang, and Szu Yu Chen
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Materials science ,business.industry ,02 engineering and technology ,Electroluminescence ,021001 nanoscience & nanotechnology ,Laser ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,law.invention ,010309 optics ,Optics ,law ,0103 physical sciences ,OLED ,Polariton ,Quantum efficiency ,Thin film ,0210 nano-technology ,business ,Absorption (electromagnetic radiation) ,Diode - Abstract
We report a highly efficient polariton organic light-emitting diode (POLED) based on an intracavity pumping architecture, where an absorbing J-aggregate dye film is used to generate polariton modes and a red fluorescent OLED is used for radiative pumping of emission from the lower polariton (LP) branch. To realize the device with large-area uniformity and adjustable coupling strength, we develop a spin-coating method to achieve high-quality J-aggregate thin films with controlled thickness and absorption. From systematic studies of the devices with different J-aggregate film thicknesses and OLED injection layers, we show that the J-aggregate film and the pump OLED play separate roles in determining the coupling strength and electroluminescence efficiency, and can be simultaneously optimized under a cavity design with a good LP-OLED emission overlap for effective radiative pumping. By increasing the absorption with thick J-aggregate film and improving the electron injection of pump OLED with Li2CO3 interlayer, we demonstrate the POLED with a large Rabi splitting energy of 192 meV and a maximum external quantum efficiency of 1.2%, a record efficiency of POLEDs reported so far. This POLED architecture can be generally applied for exploration of various organic materials to realize novel polariton devices and electrically pumped lasers.
- Published
- 2020
3. Supplementary document for Development of a highly efficient, strongly coupled organic light-emitting diode based on intracavity pumping architecture - 4851091.pdf
- Author
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Jui-Fen Chang, Lin, Tong-Yu, Chia-Fu Hsu, Szu-Yu Chen, Hong, Shun-Yu, Guo-Sian Ciou, Cheng-Chung Jaing, and Cheng-Chung Lee
- Abstract
Supplementary Materials
- Published
- 2020
- Full Text
- View/download PDF
4. Supplementary document for Development of highly efficient strongly-coupled organic light-emitting diode based on intracavity pumping architecture - 4938807.pdf
- Author
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Jui-Fen Chang, Lin, Tong-Yu, Chia-Fu Hsu, Szu-Yu Chen, Hong, Shun-Yu, Guo-Sian Ciou, Cheng-Chung Jaing, and Cheng-Chung Lee
- Abstract
supplemental 1
- Published
- 2020
- Full Text
- View/download PDF
5. Effects of Brighteners in a Copper Plating Bath on Throwing Power and Thermal Reliability of Plated Through Holes
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Yao-Lin Tsai, Yasuo Hashimoto, Chia-Fu Hsu, Wei-Ping Dow, and Chen Tzu-Chi
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Materials science ,Scanning electron microscope ,020209 energy ,General Chemical Engineering ,Metallurgy ,Nanoparticle ,chemistry.chemical_element ,02 engineering and technology ,021001 nanoscience & nanotechnology ,Chloride ,Copper ,chemistry ,Soldering ,Plating ,0202 electrical engineering, electronic engineering, information engineering ,Electrochemistry ,Copper plating ,medicine ,Surface roughness ,Composite material ,0210 nano-technology ,medicine.drug - Abstract
Plating through holes (PTH) of a printed circuit board (PCB) by copper electroplating were performed using 3-mercapo-1-1-propanesulfonate (MPS), 3-S-thiuronium propanesulfonate (UPS), and 3-(benzothiazolyl-2-mercapto)-proyl-sulfonate (ZPS) as brighteners in a copper plating bath containing CuSO 4 , H 2 SO 4 , polyethylene glycol and chloride ions in order to compare brighteners’ effects on copper throwing power (TP) of PTHs. Before PTHs, the hole walls were metallized by electroless copper deposition using copper nanoparticles (CuNPs) as catalyst rather than a traditional Sn/Pd catalyst. The accelerating effects of brighteners on copper deposition were characterized by a galvanostatic measurement with adding various brighteners in a copper plating cell. The surface roughness and morphology was measured and characterized by a profile meter and a scanning electron microscopy, respectively. Thermal reliability of plated copper films on the hole walls of the plated through hole was evaluated by thermal cycle in a soldering pot at 288 °C. The results shows that USP and ZPS more weakly depolarize copper deposition than MPS, correspondingly, they exhibit good TP of the PTHs. Good thermal reliability of plated copper film was obtained in the copper plating bath that contained 1 ppm MPS or 10 ppm UPS or 20 ppm ZPS.
- Published
- 2016
6. Optimization of the Copper Plating Process Using the Taguchi Experimental Design Method
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Hou-Chien Chang, Wei-Ping Dow, Wen-Yu Chiu, and Chia-Fu Hsu
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Microvia ,Taguchi methods ,Materials science ,Renewable Energy, Sustainability and the Environment ,Scientific method ,Metallurgy ,Materials Chemistry ,Electrochemistry ,Copper plating ,Condensed Matter Physics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Dual (category theory) - Published
- 2015
7. Synergizing Wireless Communication Technologies to Improve Internet Downloading Experiences
- Author
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Tai-Yi Huang, Chia-Fu Hsu, and Ting-Yu Lin
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Routing protocol ,business.industry ,Computer science ,Network packet ,Wireless ad hoc network ,Distributed computing ,ComputerSystemsOrganization_COMPUTER-COMMUNICATIONNETWORKS ,Throughput ,Theoretical Computer Science ,Flooding (computer networking) ,Computational Theory and Mathematics ,Hardware and Architecture ,Default gateway ,Telecommunications link ,Wireless ,The Internet ,business ,Fixed wireless ,Software ,Computer network - Abstract
Considering downloading traffic from the internet, in this paper, we propose a synergized framework (SF), consisting of heterogeneous wireless communication technologies, multi-mode (multi-interface) mobile, and fixed wireless hosts capable of operating over multiple orthogonal (non-overlapping) radio channels, to realize better downloading experiences for users via cooperation between different wireless technologies. An SyNerGized (SNG) routing protocol is devised to enable the proposed framework. Given perceived network information, SNG performs computations based on linear formulations and obtains an optimized route for packet delivery. To adapt to network dynamics, a reactive version of SNG, entitled Reactive SyNerGized (RSNG) routing protocol, is proposed to alleviate the network from constantly keeping track of link capacities within a certain scope of neighborhood. Since the downloading throughput may be bounded by either the internet gateway capacity ${\lambdab_{\mbi{gw}}}$ or ad hoc throughput ${\lambdab_{\mbi{ah}}}$ , RSNG judiciously propagates Route REQuest (RREQ) until the downloading throughput is bounded by ${\lambdab_{\mbi{ah}}}$ over the ad hoc domain, effectively eliminating unnecessary RREQ flooding. Our main objective is to improve achieved user downloading throughput via the cooperative (synergized) communication model and its corresponding routing mechanisms. Simulation results demonstrate the benefits brought by the unified architecture and corroborate the efficacy of the proposed routing techniques.
- Published
- 2014
8. Through-Hole Filling in a Cu Plating Bath with Functional Insoluble Anodes and Acetic Acid as a Supporting Electrolyte
- Author
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Wei-Ping Dow, Jian-Jun Yang, Yu-Tien Lin, Shih-Min Lin, Mei-Ling Wang, and Chia-Fu Hsu
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Renewable Energy, Sustainability and the Environment ,Chemistry ,Tetrazolium chloride ,Supporting electrolyte ,Inorganic chemistry ,Electrolyte ,Condensed Matter Physics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Anode ,Acetic acid ,chemistry.chemical_compound ,Plating ,Materials Chemistry ,Electrochemistry ,Copper plating ,Nuclear chemistry - Abstract
Through-hole filling of a printed circuit board (PCB) was carried out using a copper electroplating solution.[1-3] Tetranitroblue tetrazolium chloride (TNBT) was used as an inhibitor. Acetic acid instead of traditional H2SO4 electrolyte was employed in the copper electroplating solution. Moreover, insoluble anodes, namely dimensionally stable anodes (DSAs), composed of IrO2, Ta2O5 and Ti, instead of common soluble anodes (i.e., P-doped Cu), were employed in this work. The results show that the filling performance of the copper electroplating solution can be significantly enhanced when acetic acid and DSAs are simultaneously employed in the copper electroplating bath.
- Published
- 2013
9. Electrical impedance tomography monitoring in acute respiratory distress syndrome patients with mechanical ventilation during prolonged positive end-expiratory pressure adjustments
- Author
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Sheng Hsiang Lin, Jen Suo Cheng, Wei Chi Lin, Yen Fen Ko, Chang Wen Chen, Chia Fu Hsu, and Kuo-Sheng Cheng
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Adult ,Male ,ARDS ,Respiratory rate ,medicine.medical_treatment ,Positive-Pressure Respiration ,03 medical and health sciences ,0302 clinical medicine ,Fraction of inspired oxygen ,Electric Impedance ,Tidal Volume ,Medicine ,Humans ,030212 general & internal medicine ,Tomography ,Tidal volume ,Positive end-expiratory pressure ,Aged ,Medicine(all) ,Mechanical ventilation ,Aged, 80 and over ,lcsh:R5-920 ,Respiratory Distress Syndrome ,business.industry ,030208 emergency & critical care medicine ,General Medicine ,Oxygenation ,acute respiratory distress syndrome ,respiratory system ,Middle Aged ,medicine.disease ,respiratory tract diseases ,Anesthesia ,Linear Models ,Arterial blood ,Female ,lcsh:Medicine (General) ,business ,therapeutics ,electrical impedance tomography ,positive end-expiratory pressure ,circulatory and respiratory physiology - Abstract
Background/purposeThe time required to reach oxygenation equilibrium after positive end-expiratory pressure (PEEP) adjustments in mechanically ventilated patients with acute respiratory distress syndrome (ARDS) is unclear. We used electrical impedance tomography to elucidate gas distribution and factors related to oxygenation status following PEEP in patients with ARDS.MethodsNineteen mechanically ventilated ARDS patients were placed on baseline PEEP (PEEPB) for 1 hour, PEEPB − 4 cmH2O PEEP (PEEPL) for 30 minutes, and PEEPB + 4 cmH2O PEEP (PEEPH) for 1 hour. Tidal volume and respiratory rate were similar. Impedance changes, respiratory parameters, and arterial blood gases were measured at baseline, 5 minutes, and 30 minutes after PEEPL, and 5 minutes, 15 minutes, 30 minutes, and 1 hour after PEEPH.ResultsPaO2/fraction of inspired oxygen (P/F ratio) decreased quickly from PEEPB to PEEPL, and stabilized 5 minutes after PEEPL. However the P/F ratio progressively increased from PEEPL to PEEPH, and a significantly higher P/F ratio and end-expiratory lung impedance were found at 60 minutes compared to 5 minutes after PEEPH. The end-expiratory lung impedance level significantly correlated with P/F ratio (p
- Published
- 2014
10. A Novel Method of Forecasting CO2 Flood Performance for Various WAG Injection Schemes by Analyzing Injection Pulses
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Vinay Sahni, Chia-Fu Hsu, and Shunhua Liu
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Geography ,Flood myth ,Meteorology - Abstract
This paper presents a new method for generating dimensionless CO2 flood forecast prototypes for various injection schemes from an existing prototype. Given an existing prototype, the method described in this paper can predict an appropriate prototype for an alternating injection schedule. This methodology enables engineers to quickly generate forecast prototypes by analyzing the oil/gas production response from breaking down existing prototypes (developed either from simulation or from analog field performance) into injected CO2 pulses. A Microsoft Excel with VBA program (PULSER) based on this methodology has been successfully utilized to generate the prototypes for the fluid streams forecast of several West Texas/New Mexico CO2 flooding projects. When compared to reservoir simulation, the Pulse method is much faster in generating new prototypes and more flexible in accomodating different injection scenarios. The results from this method, full field simulation, and blind testing actual field data are remarkably consistent.
- Published
- 2014
11. Intersubband quantum-box semiconductor lasers
- Author
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Dan Botez, Jeong-Seok O, Peter S. Zory, and Chia-Fu Hsu
- Subjects
Physics ,business.industry ,Physics::Optics ,Electron ,Distributed Bragg reflector ,Laser ,Atomic and Molecular Physics, and Optics ,law.invention ,Semiconductor laser theory ,law ,Cascade ,Optoelectronics ,Electrical and Electronic Engineering ,business ,Current density ,Quantum well ,Tunable laser - Abstract
It is shown that semiconductor lasers utilizing intersubband transitions in quantum boxes, so-called intersubband quantum-box (IQB) lasers, can have significantly lower threshold current densities and operating voltages than quantum cascade (QC) lasers. In order to achieve this result, an enhancement factor of about 20 in the LO-phonon-assisted electron relaxation time is necessary. The increased gain for the radiative stage in an IQB laser eliminates the need for a multiradiative-stage structure (typically 25 stages in QC lasers). In turn, the electron injector and Bragg mirror regions on either side of the active region can be separately optimized. Due to their inherently lower input power requirements, IQB lasers operating in the mid-IR wavelength range should be capable of higher average-output powers than QC lasers at all temperatures. Furthermore, continuous-wave (CW) operation at room temperature with high wallplug efficiency becomes possible.
- Published
- 2000
12. Coulomb enhancement in InGaAs-GaAs quantum-well lasers
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Peter S. Zory, C.H. Wu, Mark A. Emanuel, and Chia-Fu Hsu
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Materials science ,business.industry ,Ingaas gaas ,Physics::Optics ,Laser ,Atomic and Molecular Physics, and Optics ,Spectral line ,Gallium arsenide ,law.invention ,chemistry.chemical_compound ,chemistry ,law ,Coulomb ,Optoelectronics ,Spontaneous emission ,Electrical and Electronic Engineering ,business ,Current density ,Quantum well - Abstract
It is shown that Coulomb enhancement (CE) has a significant influence on the spectral characteristics of optical gain and spontaneous emission in strained InGaAs quantum wells. CE-modified gain spectra are utilized to make an accurate prediction of the dependence of lasing wavelength on cavity length, Threshold-current predictions using the CE-modified gain-current relation show improved agreement with experiment.
- Published
- 1997
13. Highly Glossy Copper Foil Electrodeposition Used As a Negative Electrode of Lithium Batteries
- Author
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Chih-Han Yen, Chia-Fu Hsu, Wei-Ping Dow, Kuen-Yuen Hwang, Jui-Chang Chou, Kuei-Sen Cheng, and Huei-Fang Hwang
- Abstract
Lithium batteries have been an attractive power source for electronic product applications nowadays. The negative electrode material in the lithium battery dominates its discharge-recharge cycles and affects battery performance. Electrodeposited (ED) copper foils with excellent electrical characteristics and a low cost would be a promising candidate to replace rolled copper foils. However, ED copper foils decrease retention rate of capacity when they were used as the negative electrode material of a lithium battery. Therefore, an ED copper foil with a smooth surface on both sides has been developed for the lithium battery fabrication. In this work, 8μm thick ED copper foils were fabricated in a jet flow plating bath at a high temperature and a high current density (i.e., above 30 ASD). The surface roughness (Rz) of both mat and shiny sides is less than 2 μm. To smoothen the shiny side of the ED copper foil, a novel surface modification treatment of cathode were developed. With the pretreatment of the cathodic surface, the shiny side of the ED copper foil exhibited a smooth surface with gloss higher than 350 and a low roughness (i.e., Rz < 2 μm). For the mat side of copper foil, its gloss was higher than 500 and the roughness (Rz) was lower than 1 μm. The copper plating bath contained chloride ions, an accelerator, a suppressor and a leveler. ED copper foils were successfully fabricated with smooth surfaces on mat and shiny sides. As a consequence, large scale ED copper foils (>100 cm2) with very low roughness were fabricated, the ED nucleation was studied and the surface morphologies, roughness and structure orientation of these ED copper foils were characterized by SEM, AFM and XRD, respectively.
- Published
- 2016
14. Effects of Brighteners on Throwing Power and Thermal Reliability of Plating through Holes in a Copper Plating Bath
- Author
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Tsu-Chi Chen, Yao-Lin Tsai, Chia-Fu Hsu, and Wei-Ping Dow
- Abstract
High aspect ratio through holes are commonly designed in printed circuit boards (PCBs) with a high density interconnection. In order to achieve high copper throwing power of through holes by using plating, the copper plating bath has to be added with additives, like chloride ions, suppressors, brighteners and levelers. In this study, several brighteners were screened to understand their performance on copper throwing power of plated through holes (PTHs). The chloride ion concentration was fixed at 60 ppm and the suppressor, Polyethylene glycol, concentration was fixed at 200ppm.The brighteners were 3-mercapo-1-1-propanesulfonate(MPS), 3-S-Thiuronium-propanesulfonate (UPS) and 3-(benzothiazolyl-2-mercapto)-proyl-sulfonate(ZPS). Good throwing power of PTHs appeared at 1 ppm MPS, 20 ~ 100 ppm UPS or 20 ~ 60 ppm ZPS. Scanning Electron Microscope(SEM)shows that the electroplated morphology is related with the brightener concentration. Moreover, different brightener results in different plated copper orientation and stress in the copper deposit, which significantly influences the final thermal reliability of the PTHs. The results show that the PTHs with the highest copper TP, which were obtained at 1 ppm MPS, 10 ppm UPS, and 20 ppm ZPS, can pass the thermal shock for 5 cycles. Key words: Throwing power, Reliability, Brightener, Through hole. References: 1. W.-C. Tsai, C.-C. Wan, and Y.-Y. Wang, J. Electrochem. Soc., 150, C267 (2003). 2. C. Wang, J. Zhang, P. Yang, B. Zhang, and M. An, J. Electrochem. Soc., 160, D85 (2013).
- Published
- 2016
15. Single photon avalanche diodes (SPADs) for 1.5µm photon counting applications
- Author
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M.A. Itzler, R. Ben-Michael, Chia.-Fu Hsu, K. Slomkowski, A. Tosi, S. Cova, F. Zappa, and R. Ispasoiu
- Published
- 2007
16. Advanced high-power superluminescent light sources for environmental, chemical, and biological sensing applications
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A. Lunev, Robert Wallace Roff, D. Z. Garbuzov, Nancy Morris, J. Connolly, Chia-Fu Hsu, M. Maiorov, and Igor Kudryashov
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Materials science ,business.industry ,Sensing applications ,Power (physics) ,Gallium arsenide ,chemistry.chemical_compound ,Algaas gaas ,Optics ,chemistry ,Modulation ,Spectral width ,Optoelectronics ,business ,Diode - Abstract
In this paper we demonstrate high-power GaAs-based and InP-based superluminescent diodes (SLD) with tilted waveguides emitting in 8xx nm and 15xx nm spectral ranges respectively. The analysis of devices with different cavity lengths emphasizes the tradeoff between output power and spectral width. Power levels of about 200 mW for 820 nm SLDs and about 100 mW for 1590 nm SLDs have been demonstrated for longer cavity devices. Spectral modulation was less than 6-7% at 70-80 mW output power for both 8xx and 15xx SLDs. Simple model proposed for evaluation of spectrum modulation for both GaAs and InP devices based on semi-empirical approach is in agreement with experimental observations.
- Published
- 2004
17. Bringing Al Huwaisah's Volume to Value
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Chia Fu Hsu, J. Amthor, K. Grondin, F.C.J. Mijnssen, John Keating, and A.H. Davies
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Volume (thermodynamics) ,Mathematical analysis ,Value (mathematics) ,Geology - Abstract
The billion barrel Al Huwaisah Field is located in Northwest Oman and produces from heterogeneous rudist-dominated limestones of the Aptian Shuaiba Formation. It was discovered in 1969 and has been on-stream since 1971. Production peaked at ca. 44,000 bbl/d in 1973 after which production declined to ca. 19,000 bbl/d. Recently, production rates have increased to ca. 28,000 bbl/d, but field-wide recovery factor is still only 18% indicating that potentially large scope volumes remain in the field. In 2000, an integrated review of the Al Huwaisah field indicated a number of opportunities to mature these large scope volumes. It was noted that key to maturing these opportunities was an improved understanding of the highly complex reservoir architecture, especially regarding the distribution of fractures. Subsequently, a comprehensive fracture study was executed that included both geological information and production data. This study resulted in an improved understanding of the water movements in the field explaining the highly variable first-year net oil rates (0 – 2,500 bbl/d) of the Al Huwaisah wells. The results of the fracture study were incorporated in newly created static and dynamic models that also took into account the small-scale sedimentological heterogeneities of the Al Huwaisah reef deposits. These models were used together with the historic production review to identify production optimization opportunities, like barefoot completion strategies and water shut-off using expandable tubulars. A few of these opportunities have been implemented so far, resulting in sometimes more than 50 % increase in net oil production for the targeted wells. The barefoot completion strategy has resulted in a 10 % cost saving per well. In addition, well planning using seismic amplitude information was tested, which resulted in more than doubling the initial net production in several wells compared to the average initial well rates in Al Huwaisah. In identifying the most optimal long-term development strategy for the Al Huwaisah field, the subsurface models are being used to test the benefits of introducing water injection and miscible gas flooding. Based on the model data, a limited water injection field trial is ongoing which resulted in a ca. 20% increase in net oil production for the pilot area. Opportunities for implementing a miscible gas trial are currently being evaluated.
- Published
- 2003
18. Al-Huwaisah Reservoir: The Long Journey to Improved Oil Recovery!
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John Keating, Marcel Braas, Guy Mueller, Chia Fu Hsu, Thomas Materna, Huw Davies, and Mohammed Adil Al-Mugheiry
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Horizontal and vertical ,Enhanced recovery ,Petroleum engineering ,Water injection (oil production) ,Production (economics) ,Environmental science ,Gas lift ,Oil field - Abstract
After 30 years of production history in the Al-Huwaisah oil field of North Oman, it is still possible to bring best wells on stream. Both vertical and horizontal technologies have been implemented with variable combinations of gas-lifted or ESP completions and barefoot or lined reservoir sections. In addition, these technologies are implemented on this complex carbonate reservoir characterized by a high degree of heterogeneity embedded in four depositional environments (i.e. Channel, Fore Reef, Main Reef and Back Reef) and spread over an area of 22km by 10km with zones of strong and poor aquifer support. This necessitates the need for a sound data gathering strategy to manage the subsurface uncertainties. The improvement in recent production history was mainly the result of implementing a multidisciplinary team approach to define a more structured methodology for identifying the remaining oil targets and ranking them using basic petroleum engineering tools in a more synergistic fashion. Past operational experience has also helped in selecting the best completion and stimulation practices. The outcome of implementing these practices on such a complex field showed that improved oil recovery requires a more flexible approach in field development philosophy in the sense that not always horizontal well technology is better than vertical or lined wells are better than barefoot. The field is currently being evaluated for a possible application of Water-Alternate-Gas (or WAG) hydrocarbon recovery technique. Only parts of the field are found to be acceptable for the WAG pilot test according to the specified pre-requisites for this technology. It is evident that technology solutions for complex carbonate field such as Al-Huwaisah calls for a ‘;dynamic focus’ in the sense that different parts of the field may require different types of technologies to meet the challenges of extremely variable complexity.
- Published
- 2003
19. Effects of electron-hole attraction on quantum-well gain/absorption spectra
- Author
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P.S. Zory and Chia-Fu Hsu
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Condensed Matter::Quantum Gases ,Complex gain ,Materials science ,Condensed matter physics ,Absorption spectroscopy ,Condensed Matter::Other ,Exciton ,Electron hole ,Absorption (electromagnetic radiation) ,Attraction ,Molecular physics ,Quantum well ,Spectral line - Abstract
Gain/absorption spectra for CdZnSe quantum wells have been simulated at 300 K using a two-transition complex gain function. The incorporation of electron-hole attraction effects into this function causes two exciton-like absorption peaks to appear in the spectra at carrier densities above the Mott density.
- Published
- 2002
20. Coulomb attraction effects in CdZnSe quantum well lasers
- Author
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Chia-Fu Hsu, M.A. Haase, Peter S. Zory, and Paul Rees
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Physics ,Condensed matter physics ,Exciton ,Physics::Optics ,Plasma ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Laser ,Attraction ,law.invention ,Quantum dot laser ,law ,Coulomb ,Quantum-optical spectroscopy ,Quantum well - Abstract
It is shown that Coulomb attraction in the electron-hole plasma in CdZnSe quantum wells plays an important role in determining the observed blue-shift in lasing wavelength with increasing carrier density. The relationship between Coulomb attraction and excitonic gain is also discussed.
- Published
- 2002
21. Plating through Hole with High Throwing Power Using Dual Levelers
- Author
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Chia-Fu Hsu, Wei-Ping Dow, and Su-Mei Huang
- Abstract
In recent year, the technology evolution of wireless networks promoted the development of multifunctional pad, computers and mobile phones. The circuit density of density electron product increased as function increased. As a result, the reliability of electron products was more and more important for high density interconnect (HDI) tendency. The copper electroplating process for high throwing power of plating through holes and the thin surface layer with filling via technology were key process for HID. In this paper, copper electroplating formulas that were composed of dual levelers were studied for plating through holes with high throwing power (TP). The base plating solution contained CuSO4, H2SO4, chloride ions, polyethylene glycol (PEG), bis (3-sulfopropyl) disulfide (SPS). When leveler A was added in the base plating solution, it resulted in a smooth surface, which looked like a mirror, but its TP was not good. When leveler B was added to the base plating solution, it enhanced the TP of the plated through hole. However, the board surface was rougher than that adding leveler A. Both leveler A and leveler B could not lead to smooth surface and good TP simultaneously. Interestingly, when both leveler A and leveler B were simultaneously added in the base plating solution, they not only enhanced the TP of the plated through hole but also made the board surface smooth and bright. These results show that chemical interaction can achieve unexpected functional plating. Key words: High throwing power, high density interconnection, plating through hole and dual levelers.
- Published
- 2014
22. Gain-current relation in CdZnSe single quantum well lasers: modeling and experiment
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M. A. Haase, Chia-Fu Hsu, and Peter S. Zory
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Physics ,Condensed matter physics ,business.industry ,Electron ,Laser ,Spectral line ,Semiconductor laser theory ,law.invention ,Semiconductor ,law ,Coulomb ,Spontaneous emission ,Atomic physics ,business ,Quantum well - Abstract
Optical gain and spontaneous emission spectra are calculated for CdZnSe/ZnSSe single quantum well (QW) structures at room temperature with various many-body effects taken into account. It is found that Coulomb enhancement has a large effect on the gain-current relation derived from these spectra. When Coulomb enhancement is ignored, values of threshold current at various cavity lengths are overestimated by about 40 to 50% compared with the measured threshold currents. Good agreement with experiment is reached when Coulomb enhancement is included in the calculation.
- Published
- 1998
23. Coulomb enhancement CdZnSe single quantum well lasers
- Author
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Chia-Fu Hsu, Paul Rees, M. A. Haase, and Peter S. Zory
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Materials science ,Condensed matter physics ,Scattering ,Carrier scattering ,Band gap ,business.industry ,Physics::Optics ,Condensed Matter::Mesoscopic Systems and Quantum Hall Effect ,Laser ,law.invention ,Renormalization ,law ,Coulomb ,Optoelectronics ,business ,Quantum well ,Sign (mathematics) - Abstract
Data showing the dependence of lasing wavelength on cavity length for CdZnSe single quantum well, buried ridgeguide lasers is presented. The `slope' of the data is opposite in sign to the slope calculated from conventional theory which includes carrier scattering and bandgap renormalization. The calculated slope with Coulomb enhancement included in the model has the correct sign and the correct magnitude to within 30%. Using the Coulomb enhanced model, the key spectral features reported as evidence for an excitonic gain mechanism in room temperature CdZnSe quantum well lasers are reproduced.
- Published
- 1997
24. Intersubband laser design using a quantum box array
- Author
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Jeong Seok O, Peter S. Zory, Dan Botez, and Chia-Fu Hsu
- Subjects
Materials science ,business.industry ,Physics::Optics ,Laser ,Distributed Bragg reflector ,Semiconductor laser theory ,law.invention ,Optics ,Quantum dot laser ,law ,Cascade ,Wall-plug efficiency ,Optoelectronics ,business ,Tunable laser ,Quantum well - Abstract
It is shown that semiconductor lasers utilizing intersubband transitions in quantum boxes (IQB lasers) can have lower threshold current densities and operating voltages than quantum cascade (QC) lasers provided that a reduction factor of about 10 can be achieved in the LO phonon-assisted electron relaxation rate. The increased gain for the radiative stage in an IQB laser eliminates the need for a multi-radiative-stage structure (typically 25 in QC lasers). This allows the electron injector and Bragg mirror regions on either side of active region to be separately optimized. Due to their inherently lower input power requirements, IQB lasers operating in the mid-IR should be capable of cw operation at room temperature with high wall plug efficiency and higher average output powers than QC lasers.
- Published
- 1997
25. Internal quantum effeciency measurements of GaInP quantum well laser material using liquid contact luminescence
- Author
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Peter S. Zory, Jeong Seok O, C.L. Young, Chia-Fu Hsu, C.C. Largent, and David P. Bour
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Materials science ,business.industry ,Slope efficiency ,Quantum point contact ,Laser ,Computer Science::Other ,law.invention ,Semiconductor laser theory ,Quantum dot laser ,law ,Optoelectronics ,Quantum efficiency ,Quantum well laser ,business ,Quantum well - Abstract
A liquid contact luminescence (LCL) technique is described. LCL spectral data obtained by current injection through two GaInP quantum well laser wafers are utilized to determine the internal quantum efficiency ratio for the two wafers. This measured ratio is shown to be in good agreement with the internal quantum efficiency ratio for the two wafers as determined from conventional laser slope efficiency vs. cavity length measurements.
- Published
- 1996
26. A Pattern Steamdrive Model for Personal Computers
- Author
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Chia-Fu Hsu
- Published
- 1992
27. Electrolytic Y[sub 2]O[sub 3] Coating on IN617 Superalloy
- Author
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Chia-Fu Hsu and Shiow-Kang Yen
- Subjects
Thermogravimetric analysis ,Materials science ,Aqueous solution ,Renewable Energy, Sustainability and the Environment ,chemistry.chemical_element ,Electrolyte ,Yttrium ,Condensed Matter Physics ,Surfaces, Coatings and Films ,Electronic, Optical and Magnetic Materials ,Superalloy ,Crystallography ,chemistry.chemical_compound ,chemistry ,Materials Chemistry ,Electrochemistry ,Hydroxide ,Spectroscopy ,Deposition (law) ,Nuclear chemistry - Abstract
By means of X-ray diffraction (XRD), scanning electronic microscopy/energy dispersion spectroscopy observation, thermogravimetric analysis (TGA), differential scanning carorimeter (DSC), and cathodic polarization tests, the mechanism of electrolytic yttrium hydroxide thin-film deposition on IN617 superalloy in Y(NO 3 ) 3 aqueous solution was investigated. The cathodic polarization curve in Y(NO 3 ) 3 aqueous solution can be divided into two portions: (i) the reduction of H + and O 2 , i.e., 2H + + 2e- → H 2 and O 2 + 4H + + 4e - → 2H 2 O at -0.2 V to -0.95 V (vs saturated Ag/AgCl); (ii) the reduction of H 2 O and/or (Y + 3 )(H 2 O) 6 , i.e., 2H 2 O + 2e- → H 2 + 2 OH- and 2Y + 3 (H 2 O) 6 + 6e- → 2Y(OH) 3 .3H 2 O + 3H 2 at -0.95 V to -3 V. The best deposition condition of Y(OH) 3 .3H 2 O was conducted at the second portion. From the XRD, DSC, and TGA analyses, it was found that the as-coated film was hydrated Y(OH) 3 .3H 2 O, dehydrated into Y(OH) 3 .H 2 O at 122°C, further dehydrated into Y(OH) 3 at 366°C, condensed into YOOH at 480°C, and finally transformed into Y 2 O 3 at 550°C. Also, the electrolytic Y 2 O 3 coating film revealed the efficient retarding effects on the oxidation of IN617 superalloy in air.
- Published
- 2005
28. Analysis of laminar non-Newtonian flow and heat transfer in curved tubes
- Author
-
Chia-Fu Hsu and S. V. Patankar
- Subjects
Physics ,Environmental Engineering ,General Chemical Engineering ,Prandtl number ,Film temperature ,Laminar flow ,Heat transfer coefficient ,Mechanics ,Nusselt number ,Churchill–Bernstein equation ,Dean number ,Laminar flow reactor ,Physics::Fluid Dynamics ,symbols.namesake ,Classical mechanics ,symbols ,Biotechnology - Abstract
The governing equations for the laminar fully developed flow and heat transfer in curved tubes are solved numerically for a power-law fluid. Results for the velocity and temperature fields, the friction factor, and the Nusselt number are presented for different values of the Dean number, the Prandtl number, and the power-law index. The friction factor results are compared with available experimental data.
- Published
- 1982
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