Browsing by Author "Chen, Pei-Ling"

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A Disk-Based Mining Algorithm for Frequent Pattern Discovery from Big Data in Distributed Computing Environments
(2016-11)
Lin, Kawuu W.
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Chung, Sheng-Hao
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Hsiao, Chun-Yuan
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Lin, Chun-Cheng
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Chen, Pei-Ling
In distributed computing environments, frequent pattern mining by a multi-computing node can greatly improve mining efficiency. However, the drawback of memory limitations may cause interruption in the kernel and computing nodes when recursively building a frequent pattern (FP) tree or an FP-growth algorithm. In this paper, we propose disk-based FP-tree generation and node-based clustering mechanisms to solve the insufficient memory problem. Results from empirical evaluations show that the proposed method delivers excellent scalability.
A Disk-Based Mining Algorithm for Frequent Pattern Discovery from Big Data in Distributed Computing Environments
(2016-11-01)
Lin, Kawuu W.
;
Chung, Sheng-Hao
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Hsiao, Chun-Yuan
;
Lin, Chun-Cheng
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Chen, Pei-Ling
In distributed computing environments, frequent pattern mining by a multi-computing node can greatly improve mining efficiency. However, the drawback of memory limitations may cause interruption in the kernel and computing nodes when recursively building a frequent pattern (FP) tree or an FP-growth algorithm. In this paper, we propose disk-based FP-tree generation and node-based clustering mechanisms to solve the insufficient memory problem. Results from empirical evaluations show that the proposed method delivers excellent scalability.
Application of Porous a-Si:H Passivation Layer Deposited Using Si2H6 Precursor in Silicon Heterojunction Solar Cells
(2018-01-01)
Chen, Po-Wei
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Chen, Pei-Ling
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Hsu, Hung-Jung
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Matsui, Takuya
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Sai, Hitoshi
The improved silicon heterojunction solar cell efficiency by employing porous a-Si:H passivation layer deposited using Si2H6 precursor is presented. By introducing Si2H6 precursor into the commonly-used SiH4 plasma, it is demonstrated that the porosity of a-Si:H passivation layer can be increased significantly. A stack of the porous a-Si:H passivation layer with overlying dense a-Si:H capping layer preserves excellent interface passivation even after doped layer deposition. In the finished solar cell, improvements in Voc from 0.691 to 0.714 V and efficiency from 20.0 to 21.0% were obtained as a consequence of using porous a-Si:H passivation layer deposited under high Si2H6 concentration.
Development of Wider Bandgap n-type a-SiOx:H and mu c-SiOx:H as Both Doped and Intermediate Reflecting Layer for a-Si:H/a-Si1-xGex:H Tandem Solar Cells
(2016-07-01)
Chen, Po-Wei
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Chen, Pei-Ling
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Tsai, Chuang-Chuang
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光電工程學系
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Department of Photonics
In this work, we developed a-SiOx:H(n) and mu c-SiOx:H(n) films as n-type layer, intermediate reflecting layer (IRL), and back-reflecting layer (BRL) to improve the light management in silicon thin-film solar cells. In the development of SiOx:H films, by properly adjusting the oxygen content of the films, the optical bandgap of x-SiOx:H(n) can be increased while maintaining sufficient conductivity. Similar effect was found for a-SiOx:H(n). In a-Si:H single junction cells, employing a-SiOx:H(n) as the replacement for a-Si:H(n) resulted in a relative efficiency enhancement of 11.4% due to the reduced parasitic absorption loss. We have also found that pc-SiOx:H(n) can replace back ITO layer as BRL, leading to a relative efficiency gain of 7.6%. For a-Si:H/a-Sil..,Ge.,:H tandem cell, employing pf-SiOx:H(n) as IRL increased the current density of top cell. In addition, employing a-SiOx:H(n) as a replacement of a-Si:H(n) in the top cell increased the current density of bottom cell due to the reduction of absorption loss. Combining all the improvements, the a-Si:H/a-Si1-xGex:H tandem cell with efficiency of 9.2%, V-oc = 1.58 V, J(SC) = 8.43 mA/cm(2), and FF = 68.4% was obtained.
Development of Wider Bandgap n-type a-SiOx:H and mu c-SiOx:H as Both Doped and Intermediate Reflecting Layer for a-Si:H/a-Si1-xGex:H Tandem Solar Cells
(2016-07)
Chen, Po-Wei
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Chen, Pei-Ling
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Tsai, Chuang-Chuang
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光電工程學系
;
Department of Photonics
In this work, we developed a-SiOx:H(n) and mu c-SiOx:H(n) films as n-type layer, intermediate reflecting layer (IRL), and back-reflecting layer (BRL) to improve the light management in silicon thin-film solar cells. In the development of SiOx:H films, by properly adjusting the oxygen content of the films, the optical bandgap of x-SiOx:H(n) can be increased while maintaining sufficient conductivity. Similar effect was found for a-SiOx:H(n). In a-Si:H single junction cells, employing a-SiOx:H(n) as the replacement for a-Si:H(n) resulted in a relative efficiency enhancement of 11.4% due to the reduced parasitic absorption loss. We have also found that pc-SiOx:H(n) can replace back ITO layer as BRL, leading to a relative efficiency gain of 7.6%. For a-Si:H/a-Sil..,Ge.,:H tandem cell, employing pf-SiOx:H(n) as IRL increased the current density of top cell. In addition, employing a-SiOx:H(n) as a replacement of a-Si:H(n) in the top cell increased the current density of bottom cell due to the reduction of absorption loss. Combining all the improvements, the a-Si:H/a-Si1-xGex:H tandem cell with efficiency of 9.2%, V-oc = 1.58 V, J(SC) = 8.43 mA/cm(2), and FF = 68.4% was obtained.
Investigation of P-type Hydrogenated Nanocrystalline Silicon Grown by VHF-PECVD as Emitter in Silicon Heterojunction Solar Cells
(2018-01-01)
Chen, Pei-Ling
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Chen, Po-Wei
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Matsui, Takuya
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Sai, Hitoshi
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Tsai, Chuang-Chuang
P-type hydrogenated nanocrystalline silicon (ncSi: H(p)) films as emitter layers in silicon heterojunction solar (SHJ) cells by VHF-PECVD (65 and 100 MHz) and standard RF-PECVD (13.56 MHz) were investigated. We demonstrate that the use of VHF-PECVD is advantageous in fast nucleation in a very thin layer (< 15 nm), which in turn results in improved TCO/p contact. In addition, the deposition of nc-Si: H (p) layer by VHF-PECVD can improve the surface passivation properties as evidenced by QSSPC lifetime measurement for the solar cell precursor (i. e., pi/ c-Si/ in). These results suggest that VHF plasma generates more atomic hydrogen flux, which brings beneficial aspects both in terms of nc-Si: H growth and post-hydrogenation. Compared to our standard a-Si: H(p) emitter, the use of nc-Si: H(p) prepared by 65 MHz PECVD improved the efficiency from 19.59% to 20.50%.
Iptycenes with an acridinone motif developed through [4+2] cycloaddition of tethered naphthalene and iminoquinone via a radical reaction
(2017-06-11)
Raju, Selvam
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Annamalai, Pratheepkumar
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Chen, Pei-Ling
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Liu, Yi-Hung
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Chuang, Shih-Ching
A new class of iptycenes was developed by combining 2-(naphthalen-1-yl) anilines and p-benzoquinones through copper( II)-mediated radical cyclisation. This unusual cyclisation reaction resulted in the robust and efficient syntheses of iptycenes with an acridinone motif. These iptycenes can be further transformed into planar acridinone heterocyclics through the Diels-Alder reaction.
Optimization of mu c-Si1-xGex:H Single-Junction Solar Cells with Enhanced Spectral Response and Improved Film Quality
(2015-01-01)
Huang, Yen-Tang
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Chen, Pei-Ling
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Chen, Po-Wei
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Hsu, Hung-Jung
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Hsu, Cheng-Hang
Effects of RF power on optical, electrical, and structural properties of mu c-Si1-xGex:H films was reported. Raman and FTIR spectra from mu c-Si1-xGex:H films reflected the variation in microstructure and bonding configuration. Unlike increasing the germane concentration for Ge incorporation, low RF power enhanced Ge incorporation efficiency in mu c-Si1-xGex:H alloy. By decreasing RF power from 100 to 50 W at a fixed reactant gas ratio, the optical bandgap of mu c-Si1-xGex:H was reduced owing to the increase in Ge content from 11.2 to 23.8 at.%, while Ge-related defects and amorphous phase were increased. Consequently, photo conductivity of 1.62 x 10(-5) S/cm was obtained for the mu c-Si1-xGex:H film deposited at 60 W. By applying 0.9 mu m thick mu c-Si1-xGex:H absorber with X-C of 48% and [Ge] of 16.4 at.% in the single-junction cell, efficiency of 6.18% was obtained. The long-wavelength response of mu c-Si1-xGex:H cell was significantly enhanced compared with the mu c-Si:H cell. In the case of tandem cells, 0.24 mu m a-Si:H/0.9 mu m mu c-Si1-xGex:H tandem cell exhibited a comparable spectral response as 0.24 mu m a-Si:H/1.4 mu m mu c-Si:H tandem cell and achieved an efficiency of 9.44%.
Palladium(II)-Catalyzed Mono- and Bis-alkenylation of N-Acetyl-2-aminobiaryls through Regioselective C-H Bond Activation
(2018-04-06)
Annamalai, Pratheepkumar
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Hsu, Kou-Chi
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Raju, Selvam
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Hsiao, Huan-Chang
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Chou, Chih-Wei
We developed palladium-catalyzed oxidative coupling of olefins with N-acyl 2-aminobiaryls through a sequence of ortho C-H bond activation/alkene insertion/reductive elimination. Furthermore, we controlled the selectivity of mono- and bis-alkenylation products with the solvent effect. The developed protocol was promising for a broad substrate scope ranging from activated olefins with a wide variety of functional groups to unactivated olefins.
Palladium-Catalyzed Benzofulvenation of o-Arylanilines through C-H Bond Activation by Using Two Diarylacetylenes as an Implicit Benzofulvene
(2019-02-19)
Raju, Selvam
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Hsiao, Huan-Chang
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Thirupathi, Selvakumar
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Chen, Pei-Ling
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Chuang, Shih-Ching
We report the first example of Pd(II)-catalyzed highly step- and atom-economical benzofulvenation through free amine-directed ortho C-H bond activation of o-arylanilines. This paper presents a novel, simple, and efficient approach for the synthesis of benzofulvene derivatives from o-arylaniline substrates through C-H bond activation with two diarylacetylenes as an implicit benzofulvene unit. The reactivity of synthesized benzofulvenes toward oxidation was investigated, and they were shown to transform into phenanthridines, oxabenzofulvenes, and fluorescent polycyclics.
Palladium-Catalyzed C-H Bond Activation by Using Iminoquinone as a Directing Group and an Internal Oxidant or a Co-oxidant: Production of Dihydrophenanthridines, Phenanthridines, and Carbazoles
(2017-08-04)
Raju, Selvam
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Annamalai, Pratheepkumar
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Chen, Pei-Ling
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Liu, Yi-Hung
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Chuang, Shih-Ching
A palladium-catalyzed C-H bond activation reaction, via a redox-neutral pathway, for the preparation of dihydrophenanthridine, phenanthridine, and carbazole derivatives from biaryl 2-iminoquinones is developed. The preinstalled iminoquinone was designed to act as a directing group for ortho C-H activation and an internal oxidant or a co-oxidant. This catalysis proceeded through the following sequence: C-H bond activation, coordination and insertion of activated olefins, beta-hydride elimination, H-shift, insertion, and protonation or beta-hydride elimination. using this method without the addition of external oxidants. In addition, carbazoles can be prepared efficiently by
Study of Transition Region of p-Type SiOx:H as Window Layer in a-Si:H/a-S1-yGey:H Multijunction Solar Cells
(2016-01-01)
Chen, Pei-Ling
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Chen, Po-Wei
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Tsai, Chuang-Chuang
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光電工程學系
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Department of Photonics
We have studied the p-type hydrogenated silicon oxide (SiOx:H) films prepared in the amorphous-to-microcrystalline transition region as a window layer in a-Si:H/a-S1-yGey:H multijunction solar cells. By increasing the H-2-to-SiH, flow ratio (R,) from 10 to 167, the SiOx:H(p) films remained amorphous and exhibited an increased hydrogen content from 10.2% to 12.2%. Compared to the amorphous SiOx:H(p) film prepared at low R-H2, the SiOx:H(p) film deposited at RH, of 167 exhibited a higher bandgap of 2.04 eV and a higher conductivity of 1.15 x 10(-5)S/cm. With the employment of SiOx:H(p) films prepared by increasing RH, from 10 to 167 in a-Si:H single-junction cell, the FF improved from 65% to 70% and the efficiency increased from 7.4% to 8.7%, owing to the enhanced optoelectrical properties of SiOx:H(p) and the improved p/i interface. However, the cell that employed Si0,:14(p) film with RH, over 175 degraded the p/i interface and degraded the cell performance, which were arising from the onset of crystallization in the window layer. Compared to the cell using standard a-SiC,:H(p), the a-Si:H/a-S1-yGey:H tandem cells employing SiOx:H(p) deposited with R-H2, of 167 showed an improved efficiency from 9.3% to 10.3%, with 17, of 1.60 V, J(sc) of 9.3 mA/cm(2), and FF of 68.9%.
Synthesis, Isolation, and Characterization of Mono- and Bis-norbornene-Annulated Biarylamines through Pseudo-Catellani Intermediates
(2019-02-15)
Annamalai, Pratheepkumar
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Hsiao, Huan-Chang
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Raju, Selvam
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Fu, Yi-Hsuan
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Chen, Pei-Ling
A palladium-catalyzed C-H functionalization of an external ring of N-acyl 2-aminobiaryl with bicyclo[2.2.1]-hept-2-ene (norbornene) via multiple C-H bond activations was developed. This study is the first report of the formation of bis-norbornene annulated biarylamines isomers (syn-3a'/anti-3a' = 36:64) from multiple C-H bond functionalizations. Additionally, nondirected C-H bond functionalization at the C-4' position with alkenes rendered complete C-H functionalization of five C-H bonds that formed a stable hexasubstituted benzene ring.
Wide-Range Enhancement of Spectral Response by Highly Conductive and Transparent mu c-SiOx:H Doped Layers in mu c-Si:H and a-Si:H/mu c-Si:H Thin-Film Solar Cells
(2016-01-01)
Chen, Pei-Ling
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Chen, Po-Wei
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Hsiao, Min-Wen
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Hsu, Cheng-Hang
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Tsai, Chuang-Chuang
Theenhancement of optical absorption of silicon thin-film solar cells by the p-and n-type mu c-SiOx:H as doped and functional layers was presented. The effects of deposition conditions and oxygen content on optical, electrical, and structural properties of mu c-SiOx:H films were also discussed. Regarding the doped mu c-SiOx:H films, the wide optical band gap (E-04) of 2.33 eV while maintaining a high conductivity of 0.2 S/cm could be obtained with oxygen incorporation of 20 at.%. Compared to the conventional mu c-Si:H(p) as window layer in mu c-Si:H single-junction solar cells, the application of mu c-SiOx:H(p) increased the V-OC and led to a significant enhancement in the short-wavelength spectral response. Meanwhile, the employment of mu c-SiOx:H(n) instead of conventional ITO as back reflecting layer (BRL) enhanced the external quantum efficiency (EQE) of mu c-Si:H single-junction cell in the long-wavelength region, leading to a relative efficiency gain of 10%. Compared to the reference cell, the optimized a-Si:H/mu c-Si:H tandem cell by applying p-and n-type mu c-SiOx:H films achieved a V-OC of 1.37V, J(SC) of 10.55 mA/cm(2), FF of 73.67%, and efficiency of 10.51%, which was a relative enhancement of 16%.