Effect of rapid thermal oxidation on structure and photoelectronic properties of silicon oxide in monocrystalline silicon solar cells

Chung Ping Liu,Ming Wei Chang,Chuan Lung Chuang 한국물리학회 2014 Current Applied Physics Vol.14 No.5

This paper concerns the topic of surface passivation properties of rapid thermal oxidation on p-type monocrystalline silicon wafer for use in screen-printed silicon solar cells. It shows that inline thermal oxidation is a very promising alternative to the use of conventional batch type quartz tube furnaces for the surface passivation of industrial phosphorus-diffused emitters. Five minutes was the most favorable holding time for the rapid thermal oxidation growth of the solar cell sample, in which the average carrier lifetime was increased 19.4 ms. The Fourier transform infrared spectrum of the rapid thermal oxidation sample, whose structure was Al/Al-BSF/p-type Si/n-type SiP/SiO2/SiNx/Ag solar cell with an active area of 15.6 cm2, contained an absorption peak at 1085 cm1, which was associated with the SieO bonds in silicon oxide. The lowest average reflectance of this sample is 0.87%. Furthermore, for this sample, its average of internal quantum efficiency and conversion efficiency are respectively increased by 8% and 0.23%, compared with the sample without rapid thermal oxidation processing.

Formation of CuInGaSe2 Thin Film Photovoltaic Absorber by Using Rapid Thermal Sintering of Binary Nanoparticle Precursors

Chung Ping Liu,Ming Wei Chang,Chuan Lung Chuang 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.63 No.11

It was known that properties of copper-indium-gallium-diselenide (CIGS) thin films were evidentlyaffected by precursor nanoparticle-ink and sintering technology. The nanoparticles were fabricatedby using a rotary ball-milling (RBM) technique. After RBM, the particle size of the agglomeratedCIGS powder was smaller than 100 nm. The nanoparticle ink was printed onto a Mo/soda limeglass substrate and baked at a low temperature to remove solvents and to form a dry precursor. Crystallographic, morphological, and stoichiometric properties of films were then obtained by usingthe precursor CIGS samples sintered at various heating rates in a non-vacuum environment withoutselenization. Analytical results revealed that the 2-theta data of the sample sintered at a heatingrate of 15 C/s were the closest to the data on the JCPDS card for Cu(Ga0.3In0.7)Se2.0 because theirangles were 26.8, 44.5, and 52.7, respectively. In addition, analytical results indicated that theCIGS absorption layer prepared at a heating rate of 15 C/s had a chalcopyrite structure and favorablecompositions. For this sample, the mole ratio of Cu:In:Ga:Se was equal to 0.98:0.81:0.28:1.93,and related ratios of Ga/(In+Ga) and Cu/(In+Ga) were 0.26 and 0.90, respectively.

Influence of the Ratio of Surfactant Additives on the Anisotropic Etching Process Used to Make Small Pyramids for Use in Solar Cells

Chung Ping Liu,Ming Wei Chang,Chuan Lung Chuang 한국물리학회 2014 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.64 No.9

This paper focuses on surfactant additives (SA) that are used in alkaline etching of p-typemonocrystalline silicon wafers for use in screen-printed silicon solar cells. An Al/p-type Si/ntypeSiP/SiNx/Ag solar cell with an active area of 15.6 cm2 was fabricated. The highest measuredefficiency of the solar cells was 19.24%, which proves that the SA method is highly efficient for fabricatingmonocrystalline silicon solar cells. The results show that 0.4 L of SA is the most favorablevolume for alkaline etching of solar-cell samples. Samples etched at this volume exhibit the lowestaverage reflectance of 0.596%, an average internal quantum efficiency (IQE) gain of 5.6% and anefficiency gain of 0.84%, thus showing the SA method to be an efficient anisotropic etching process. In addition, the cell with the highest efficiency had an increase of 4.57% in power, an increase of3.1% in the short-circuit current, and an increase of 1.43% in the open-circuit voltage. In summary,microstructural, reflectance, IQE, and I − V measurements revealed that the best cell was formedusing an optimal SA volume of 0.4 L.

An Efficient Load Balancing Scheme for Multi-Gateways in Wireless Mesh Networks

( Jun Ping Liu ),( Sang Hwa Chung ) 한국정보처리학회 2013 Journal of information processing systems Vol.9 No.3

In Wireless Mesh Networks (WMNs), we usually deploy multiple Internet Gateways (IGWs) to improve the capacity of WMNs. As most of the traffic is oriented towards the Internet and may not be distributed evenly among different IGWs, some IGWs may suffer from bottleneck problem. To solve the IGW bottleneck problem, we propose an efficient scheme to balance the load among different IGWs within a WMN. Our proposed load-balancing scheme consists of two parts: a traffic load calculation module and a traffic load migration algorithm. The IGW can judge whether the congestion has occurred or will occur by using a linear smoothing forecasting method. When the IGW detects that the congestion has occurred or will occur, it will firstly select another available IGW that has the lightest traffic load as the secondary IGW and then inform some mesh routers (MPs) which have been selected by using the Knapsack Algorithm to change to the secondary IGW. The MPs can return to their primary IGW by using a regression algorithm. Our Qualnet 5.0 experiment results show that our proposed scheme gives up to 18% end-to-end delay improvement compared with the existing schemes.

Dietary Ziziphus jujuba Fruit Influence on Aberrant Crypt Formation and Blood Cells in Colitis-Associated Colorectal Cancer Mice

Periasamy, Srinivasan,Liu, Chung-Teng,Wu, Wang-Hung,Chien, Se-Ping,Liu, Ming-Yie Asian Pacific Journal of Cancer Prevention 2015 Asian Pacific journal of cancer prevention Vol.16 No.17

Ziziphus jujuba (ZJ) fruit is rich in bioactive functional components such as polysaccharides, triterpenoid acid, flavonoids and oleamide. It has been commonly used in the treatment of various diseases including diabetes, digestive disorders, diarrhea, skin infections, liver and urinary diseases. However, its dietary effect on chemoprevention of colon cancer has never been studied. The present study was to evaluate the protective effects of dietary ZJ on colitis-associated colon carcinogenesis in azoxymethane (AOM)-dextran sodium sulphate (DSS)-treated mice. AOM was injected (10 mg/kg b.wt., i.p.) and three cycles of 2% DSS in drinking water for 7 days with 14 days of normal drinking water in-between was administered to induce colitis-associated colon cancer. ZJ fruit was supplemented in feed as 5 and 10%. Dietary ZJ significantly attenuated aberrant crypt foci (ACF) formation thereby decreasing the progression of hyperplasia to dysplasia. In addition, it significantly reduced circulating white blood cells, lymphocytes, neutrophils, monocytes, eosinophils, basophils and platelets compared to colon cancer mice. We conclude that ZJ supplementation delayed the progression of colon cancer from hyperplasia to dysplasia and ultimately adenocarcinoma and cancer. In addition, it decreased circulating tumor-related leucocytes, main regulators of cancer inflammation. Therefore, dietary consumption of ZJ fruit attenuated the formation of ACF and delayed the progression of colon cancer.

The Compressive Strength of Slender C-shaped Cold-formed Steel Members with Web Openings

Dung M. Lue,Ping-Tsung Chung,Jui-Ling Liu,Chi-Ling Pan 한국강구조학회 2009 International Journal of Steel Structures Vol.9 No.3

This study investigated the compressive strength of slender C-shaped cold-formed steel members with web openings. The effective sectional area concept was adopted to conduct the analysis of cold-formed compressive members. The load-carrying capacity of compression member was calculated based on the sectional effective width as described in the AISI Standard. The study tested a total of 21 channel specimens including C-shaped cross-sections with and without web openings. Comparisons were made between the test results and the predictions based on both the AISI Standard and the ANSYS analysis. The results indicated that all the observed failure modes were of the flexural-torsional buckling classification. It was found that the reduction in the compression strength of the specimens with web openings seems to be negligible. In addition, the predictions based on the AISI Standard were conservative as compared with the test results of the specimens with web openings. Moreover, it appeared that the ANSYS finite element analysis was able to predict the ultimate loads and failure modes of the specimens. In the absence of test data and for the purpose of preliminary design, the ANSYS appears to provide quite an encouraging prediction capability. This study investigated the compressive strength of slender C-shaped cold-formed steel members with web openings. The effective sectional area concept was adopted to conduct the analysis of cold-formed compressive members. The load-carrying capacity of compression member was calculated based on the sectional effective width as described in the AISI Standard. The study tested a total of 21 channel specimens including C-shaped cross-sections with and without web openings. Comparisons were made between the test results and the predictions based on both the AISI Standard and the ANSYS analysis. The results indicated that all the observed failure modes were of the flexural-torsional buckling classification. It was found that the reduction in the compression strength of the specimens with web openings seems to be negligible. In addition, the predictions based on the AISI Standard were conservative as compared with the test results of the specimens with web openings. Moreover, it appeared that the ANSYS finite element analysis was able to predict the ultimate loads and failure modes of the specimens. In the absence of test data and for the purpose of preliminary design, the ANSYS appears to provide quite an encouraging prediction capability.

Grey Neural Network-Based Forecasting System for Vision-Guided Robot Trajectory Tracking

Shih-Hung Yang,Chung-Hsien Chou,Chen-Fang Chung,Wen-Pang Pai,Tse-Han Liu,Yung-Sheng Chang,Jung-Che Li,Huan-Chan Ting,Yon-Ping Chen 제어로봇시스템학회 2011 제어로봇시스템학회 국제학술대회 논문집 Vol.2011 No.10

This paper presents a grey neural network-based forecasting system (GNNFS) in solving the prediction problem. GNNFS adopts a grey model to predict the signal and a neural network (NN) to forecast the prediction error of the grey model. A sequential batch learning (SBL) is developed to adjust the weights of the NN. The proposed GNNFS is applied to a binocular robot, called an Eye-Robot, for human-robot interaction which involved predicting the trajectory of a participant’s hand and tracking the hand. By applying the SBL, the GNNFS can gradually learn to predict the trajectory of the hand and track it well. The experimental results show that the GNNFS can carry out the SBL in real-time for vision-guided robot trajectory tracking.

Shear behavior of reinforced HPC beams made of a low cement content without shear reinforcements

Chao-Wei Tang,Yu-Ping Chen,How-Ji Chen,Chung-Ho Huang,Tsang-Hao Liu 사단법인 한국계산역학회 2013 Computers and Concrete, An International Journal Vol.11 No.1

High-performance concrete (HPC) usually has higher paste and lower coarse aggregate volumes than normal concrete. The lower aggregate content of HPC can affect the shear capacity of concrete members due to the formation of smooth fractured surfaces and the subsequent development of weak interface shear transfer. Therefore, an experimental investigation was conducted to study the shear strength and cracking behavior of full-scale reinforced beams made with low-cement-content high-performance concrete (LcHPC) as well as conventional HPC. A total of fourteen flexural reinforced concrete (RC) beams without shear reinforcements were tested under a two-point load until shear failure occurred. The primary design variables included the cement content, the shear span to effective depth ratio (a/d), and the tensile steel ratio (ρw). The results indicate that LcHPC beams show comparable behaviors in crack and ultimate shear strength as compared with conventional HPC beams. Overall, the shear strength of LcHPC beams was found to be larger than that of corresponding HPC beams, particularly for an a/d value of 1.5. In addition, the crack and ultimate shear strength increased as a/d decreased or ρw increased for both LcHPC beams and HPC beams. This investigation established that LcHPC is recommendable for structural concrete applications.

Adjusting optical resonance thickness to increase the conversion efficiency of polymer solar cells

Yu Sheng Tsai,Jian-Shian Lin,Wei-Ping Chu,Po-Hsun Wang,Fuh-Shyang Juang,Ming-Hua Chung,Chin-Ming Chen,Mark O. Liu 한국물리학회 2010 Current Applied Physics Vol.10 No.3

The derivatives of C60, [6,6]-phenyl C61-butyric acid methyl ester (PCBM), and 3-hexylthiophene (P3HT)were dissolved in DCB solvent, then spin coated into an active layer for polymer solar cells. The experimental parameters were studied carefully to obtain the optimum power conversion efficiency (PCE). The primary process for generation of photocurrent in an organic photovoltaic device is the generation of bound electron–hole pairs (excitons) by absorption of energy (photons) from the optical electric field. Modeling was based on the assumption that the photocurrent generation process is the result of the creation and diffusion of photogenerated species (excitons), which are dissociated by charge transfer at the active layer. Improve organic optics absorb by insert organic layer (CuPc or C60) at the active layer/Al interface. This research is divided into two components. First part, we use n-type C60 as transmission layer. When an optimum thickness of C60 is 5 nm, the Jsc of polymer solar cell can be increased from 7.26 mA/㎠ to 7.7 mA/㎠. The Voc decrease is because the energy level of C60 LUMO (lowest unoccupied molecular orbital) at 4.5 eV is higher than the 3.7 eV of PCBM. Second part, we use p-type CuPc as transmission layer. When an optimum thickness of CuPc is 3 nm, the short circuit photo-current density (Jsc) and open circuit voltage (Voc) of polymer solar cell can be increased from 7.26 mA/㎠ to 8.0 mA/㎠ and 0.56–0.58 V, respectively. The reason is the same as C60. The Voc increase is because the energy level of CuPc LUMO (lowest unoccupied molecular orbital) at 3.1 eV is lower than the 3.7 eV of PCBM. The Jsc increase is because the 3 nm of CuPc leads to a constructive interference happened in the active layer and thus optical absorption increases. In this study we used 3 nm of CuPc at the active layer/Al interface to enhance the short circuit current density, and the efficiency was increased to 2.94%.

Effects of 5HT1A Activation on Depression Profile Following 5-HT Depletion in Rats Lacking Social Attachment Since Weanling

Kuo-Jung Chang,Yu-Jung Chen,Jing-Yi Chung,Chen-Cheng Lin,Yia-Ping Liu 대한신경정신의학회 2018 PSYCHIATRY INVESTIGATION Vol.15 No.10

Objective: Post weanling isolation-reared (IR) rats are featured with depressive phenotype, yet its mechanism is not clearly defined particularly in terms of the involvement of central 5-HT1A receptors. The present study aims to examine the effects of 5HT1A activation on forced swim test (FST) in IR rats following 5-HT depletion. Methods: Social control (SOC) and IR rats received an intracerebraoventricular (ICV) injection of 5-HT depletion agent, 5,7-DHT. 14days after the surgery, rats were assessed their performance in FST with or without the challenge with a 5-HT1A agonist, 8-OH-DPAT. Rats were then sacrificed for analyzing their 5-HT tissue levels and the expressions of their 5-HA1A receptors in prefrontal cortex (PFC), hippocampus (HPX), and amygdala (AMY). Results: 5,7-DHT decreased the tissue concentration of 5-HT in both IR and SOC rats. IR rats were more immobile and less sensitive to the lesion-induced immobility, however this effect was reversed by acute challenge of 8-OH-DPAT. 5,7-DHT lesion increased the expression of PFC 5-HT1A receptors. Conclusion: The integrity of central 5-HT system is developmentally crucial for the 5-HT1A-relevant depression profile in rats of social isolation.