Impact of Structural Defect Density on Gettering of Transition Metal Impurities during Phosphorus Emitter Diffusion in Multi-Crystalline Silicon Solar Cell Processing

박용국,Jinggang Lu,박진홍,George Rozgonyi 대한금속·재료학회 2015 ELECTRONIC MATERIALS LETTERS Vol.11 No.4

The impact of structural defect density on gettering of transition metal impurities during phosphorous emitter diffusion has been investigated using a pair of multi-crystalline silicon (mc-Si) wafers. Chromium (Cr) impurities incorporated during growth were identified by deep level transient spectroscopy (DLTS) and used to evaluate the gettering efficiency. The Cr impurity concentration in the low defect density region of mc-Si wafers was reduced from ~3.5 × 1013 cm−3 to ~1.7 × 1012 cm−3 after phosphorous diffusion gettering (PDG), while for the high defect density region, there is no appreciable variation in the Cr concentration which only changed from ~3.0 to ~2.2 × 1012 cm−3 following PDG. It was concluded that the gettering process is not effective for highly defective regions of mc-Si wafers due to the ineffective impurity release from structural defects during the PDG process.

The Influence of Hydrogenation on the Electrical Properties of Impurity-Contaminated Silicon Grain Boundaries

박영국,Jinggang Lu,박진홍,George Rozgonyi 대한금속·재료학회 2015 ELECTRONIC MATERIALS LETTERS Vol.11 No.6

In this article, the impact of hydrogenation on the electrical properties of impurity (Fe)-contaminated silicon grain boundaries (GBs) is investigated using capacitance-voltage (C-V) and capacitance transient (C-t) techniques with hybrid orientation direct-silicon-bonded (DSB) wafers. The samples consist of a 2.3 μm thick (110) Si layer on a p-type (100) Si substrate produced via hydrophilic wafer bonding, cleavage, and epithickening. It was found that for a relatively clean GB, the density of the GB states (DGB) is ~6 × 1012 eV−1cm−2, and the charge neutral level is ~0.53 eV from the valance band. DGB increases to more than 2 × 1013 eV−1cm−2 after the Fe contamination, which is reduced to ~1 × 1013 eV−1cm−2 after the hydrogenation treatment. The charge neutral level, which shifts toward the conduction band after the Fe contamination, is reversed after hydrogenation.

Research on Information Entropy Measure based on Collaborative Filtering Algorithm

Jingxia Guo,Jinggang Guo 보안공학연구지원센터 2016 International Journal of Hybrid Information Techno Vol.9 No.3

Most existing calculations of similarities suffer from data sparsity and poor prediction quality problems. For this issue, we proposed a similarity measurement algorithm based on entropy. The entropy is computed by the difference of two users’ ratings, and we also consider the size of their common rated items, the size is bigger, the weight of their similarity is higher. Experiments show that the algorithm effectively solves the problem of the inaccuracy of similarities in data sparsity or small size neighborhood environments, and outperforms other state-of-the-art CF algorithms and it is more robust against data sparsity.

Corrosion release behavior of alloy 690 and its application in high-temperature water with Zn injection

Jiapeng Liao,Yousen Hu,Jinggang Li,Desheng Jin,Shuqi Meng,Tianming Ruan,Yisong Hu,Ziyu Zhang 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.3

Corrosion release behavior of Alloy 690 in high-temperature water was investigated under the conditionsof injected Zn concentrations of 0 ppb, 10 ppb and 50 ppb. A protective oxide film composed of Zn(FexCr1-x)2O4 and Cr2O3 was formed with Zn injection, resulting in a better corrosion resistance. In comparisonwith the Zn-free condition, the corrosion release rate under the Zn-injection conditions was smaller. Thecorrosion release inhibiting factors were 1.7 and 1.9 under the conditions of 10 ppb and 50 ppb Zninjectionrespectively. A foreseen application of the corrosion and corrosion release rates has beenproposed and discussed.

Waste Cellulose Fibers Reinforced Polylactide Toughened by Direct Blending of Epoxidized Soybean Oil

Sakil Mahmud,Yu Long,Jinggang Wang,Jinyue Dai,Ruoyu Zhang,Jin Zhu 한국섬유공학회 2020 Fibers and polymers Vol.21 No.12

An eco-friendly method has been used to synthesize ductile and toughen composites from completely renewableresources by exploring poly(lactic acid) (PLA)’s sophisticated properties in terms of strength, stiffness as well as itsbrittleness. Due to their excellent mechanical properties and potential for sustainable manufacturing, nano-cellulose as a biobasedorganic filler, have been broadly used in a variety of polymer reinforcement. Herein, waste cellulose fibers (WCF)within the nanometer range were used as a filler to blend with PLA using lab-scale twin-extruder, with and withoutepoxidized soybean oil (ESO) as a reactive plasticizer. To investigate their effect on the mechanical properties like Young’smodulus, strength, toughness, and ductility, various constituents of ingredients were selected. An increase in elongation-atbreak(5.1 to 60.8 %), bending strain (5.9 to 9.4 %) and impact strength (2.05 to 6.1 kJ/m2) in comparison to neat PLA wasfound in PLA/WCF/ESO ternary composites, leading to reduced glass transition (Tg) and crystallization temperature (Tc) asconfirmed by a differential scanning calorimetry (DSC) measurements. An increase in char yield was also observed from thethermogravimetric analysis (TGA), which was clearly associated with the flame potency. Chemical interactions wereinvestigated by Fourier transform infrared (FTIR) spectroscopy by examining shifts in peak positions. A scanning electronmicroscope (SEM) was utilized systematically to analyze the toughening mechanism.

Microbial composition in different gut locations of weaning piglets receiving antibiotics

Li, Kaifeng,Xiao, Yingping,Chen, Jiucheng,Chen, Jinggang,He, Xiangxiang,Yang, Hua Asian Australasian Association of Animal Productio 2017 Animal Bioscience Vol.30 No.1

Objective: The aim of this study was to examine shifts in the composition of the bacterial population in the intestinal tracts (ITs) of weaning piglets by antibiotic treatment using high-throughput sequencing. Methods: Sixty 28-d-old weaning piglets were randomly divided into two treatment groups. The Control group was treated with a basal diet without antibiotics. The Antibiotic group's basal diet contained colistin sulfate at a concentration of 20 g per ton and bacitracin zinc at a concentration of 40 g per ton. All of the pigs were fed for 28 days. Then, three pigs were killed, and the luminal contents of the jejunum, ileum, cecum, and colon were collected for DNA extraction and high-throughput sequencing. Results: The results showed that the average daily weight gain of the antibiotic group was significantly greater (p<0.05), and the incidence of diarrhea lower (p>0.05), than the control group. A total of 812,607 valid reads were generated. Thirty-eight operational taxonomic units (OTUs) that were found in all of the samples were defined as core OTUs. Twenty-one phyla were identified, and approximately 90% of the classifiable sequences belonged to the phylum Firmicutes. Forty-two classes were identified. Of the 232 genera identified, nine genera were identified as the core gut microbiome because they existed in all of the tracts. The proportion of the nine core bacteria varied at the different tract sites. A heat map was used to understand how the numbers of the abundant genera shifted between the two treatment groups. Conclusion: At different tract sites the relative abundance of gut microbiota was different. Antibiotics could cause shifts in the microorganism composition and affect the composition of gut microbiota in the different tracts of weaning piglets.

Preliminary conceptual design of a small high-flux multi-purpose LBE cooled fast reactor

Xiong Yangbin,Duan Chengjie,Zeng Qin,Ding Peng,Song Juqing,Zhou Junjie,Xu Jinggang,Yang Jingchen,Li Zhifeng 한국원자력학회 2022 Nuclear Engineering and Technology Vol.54 No.8

The design concept of a Small High-flux Multipurpose LBE(Lead Bismuth Eutectic) cooled Fast Reactor (SHMLFR) was proposed in the paper. The primary cooling system of the reactor is forced circulation, and the fuel element form is arc-plate loaded high enrichment MOX fuel. The core is cylindrical with a flux trap set in the center of the core, which can be used as an irradiation channel. According to the requirements of the core physical design, a series of physical design criteria and constraints were given, and the steady and transient parameters of the reactor were calculated and analyzed. Regarding the thermal and hydraulic phenomena of the reactor, a simplified model was used to conduct a preliminary analysis of the fuel plates at special positions, and the temperature field distribution of the fuel plate with the highest power density under different coolant flow rates was simulated. The results show that the various parameters of SHMLFR meet the requirements and design criteria of the physical design of the core and the thermal design of the reactor. This implies that the conceptual design of SHMLFR is feasible