Green synthesis of finely-dispersed highly bactericidal silver nanoparticles via modified Tollens technique

Anh-Tuan Le,P.T. Huy,Phuong Dinh Tam,Tran Quang Huy,A.A. Kudrinskiy,Yu A. Krutyakov 한국물리학회 2010 Current Applied Physics Vol.10 No.3

In this article, we represent a versatile and effective technique which using non-toxic chemicals to prepare stable aqueous dispersions of silver nanoparticles (NPs) via modified Tollens process. It was shown that as-prepared silver colloids consisted of finely-dispersed NPs with average diameter about 10 nm and a relatively narrow size distribution. Moreover, they could be stored very stable after several months without observation of aggregates or sedimentation. In comparison with previous works where Tollens process was being used, we for the first time applied UV-irradiation simultaneously with glucose reduction of silver salt through NPs preparation. The colloidal solutions of silver NPs were found to exhibit a high antibacterial activity against gram-negative Escherichia coli. The concentration of silver leading to a complete inhibition of bacteria growth was revealed as low as at 1.0 ㎍ml-1 and found much lower compared to earlier reports. These advantages of aqueous dispersions of silver NPs make them ideal for green industrial, medicinal, microbiological and other applications.

Indium-Tin-Oxide-Based Stacked Layer as an Anti-Reflection Electrode Prepared by Onlique-Angle Sputtering Method

Anh Huy Tuan Le,Yonghyeon Cho(조용현),Euncheol Cho(조은철),Shihyun Ahn(안시현),Hyeongsik Park(박형식),Shahzada Qumar Hussain,Junsin Yi(이준신) 한국신재생에너지학회 2018 한국신재생에너지학회 학술대회논문집 Vol.2018 No.4

Negotiating with intimacy : Being a good Vietnamese mother in Taiwan

Huy Le Anh HUYNH,Tuan Quoc HUYNH Asian Center for Women's Studies : Ewha Womans Uni 2020 Asian Journal of Women's Studies(AJWS) Vol.26 No.4

Vietnamese immigrant women in Taiwan often encounter difficulties in being “good mothers,” compared to their local counterparts. Their mothering is stigmatized and they are represented as “alien wombs” or are said to be “unfit” for reproductive roles. This has negative impact on the next generation of children of mixed ethnicity. Drawing upon in-depth interviews with 16 Vietnamese immigrant women married to Taiwanese men, we used a feminist perspective on mothering to explore intimacy as experienced within unhappy marital lives. We found that to become “good mothers” in the eyes of the society they now live in, such women try to build harmonious familial relationships with family members. They do this by attempting to change people’s negative ideas and images regarding them and doing whatever they can for their families and society. We conclude that these women use intimacy with their children as a strategy for being respected as mothers in Taiwan, the country in which they now live. Những người phụ nữ Việt Nam nhập cư vào Đài Loan theo hình thức hôn nhân thường gặp những khó khăn trong việc trở thành một người mẹ tốt, so với những người phụ nữ bản địa. Việc làm mẹ thường bị kỳ thị và họ bị xem là “những con sâu bệnh” hoặc được cho là “không phù hợp” với vai trò tái sản xuất. Điều này đã tác động tiêu cực đến thế hệ tiếp theo - những đứa trẻ hai dòng máu. Dựa trên các cuộc phỏng vấn sâu với 16 người phụ nữ Việt nam nhập cư thông qua hình thức kết hôn với những đàn ông Đài Loan, bài nghiên cứu sử dụng quan điểm nữ quyền về việc làm mẹ và khám phá ra sự “thân mật” như là một sự trải nghiệm trong cuộc sống hôn nhân không hạnh phúc. Nghiên cứu này phát hiện ra rằng để trở thành “người mẹ tốt” trong xã hội nơi mà họ đang sống, những người phụ nữ này cố gắng xây dựng mối quan hệ hòa thuận với các thành viên trong gia đình. Họ nỗ lực thay đổi những định kiến và hình ảnh tiêu cực của mọi người về bản thân mình và làm bất cứ điều gì họ có thể làm cho gia đình và xã hội. Chúng tôi kết luận rằng sự “thân mật” có thể được sử dụng như một chiến lược để nhận được sự tôn trọng như những người mẹ Đài Loan.

Study on the Structural and Mechanical Characteristics of ITO Films Deposited by Pulsed DC Magnetron Sputtering

강준영,Anh Huy Tuan Le,Hyeongsik Park,Yongjun Kim,Junsin Yi,Sunbo Kim 한국전기전자재료학회 2016 Transactions on Electrical and Electronic Material Vol.17 No.6

The mechanical properties of ITO films such as adhesion and internal stress are very important for the commercialapplication of solar cell devices. We report high quality pulsed DC magnetron sputtered ITO films deposited on siliconand glass substrates with low resistivity and high transmittance for various working pressures ranging from 0.96 to3.0 mTorr. ITO films showed the lowest resistivity of 2.68×10-4 Ω·cm, high hall mobility of 46.89 cm2/V.s, and hightransmittance (>85%) for the ITO films deposited at a low working pressure of 0.99 mTorr. The ITO films depositedat a low working (0.96 mTorr) pressure had both amorphous and polycrystalline structures and were found to havecompressive stress while the ITO films deposited at higher temperature than 0.99 mTorr was mixture of amorphousand polycrystalline and was found to have tensile stress.

Oblique-angle sputtering에 의한 Indium tin oxide 이중층 반사방지막 특성에 관한 연구

김용준,Anh Huy Tuan Le,김선보,이준신 한국진공학회 2016 한국진공학회 학술발표회초록집 Vol.2016 No.2

Study on the Structural and Mechanical Characteristics of ITO Films Deposited by Pulsed DC Magnetron Sputtering

Kang, Junyoung,Le, Anh Huy Tuan,Park, Hyeongsik,Kim, Yongjun,Yi, Junsin,Kim, Sunbo The Korean Institute of Electrical and Electronic 2016 Transactions on Electrical and Electronic Material Vol.17 No.6

The mechanical properties of ITO films such as adhesion and internal stress are very important for the commercial application of solar cell devices. We report high quality pulsed DC magnetron sputtered ITO films deposited on silicon and glass substrates with low resistivity and high transmittance for various working pressures ranging from 0.96 to 3.0 mTorr. ITO films showed the lowest resistivity of $2.68{\times}10^{-4}{\Omega}{\cdot}cm$, high hall mobility of $46.89cm^2/V.s$, and high transmittance (>85%) for the ITO films deposited at a low working pressure of 0.99 mTorr. The ITO films deposited at a low working (0.96 mTorr) pressure had both amorphous and polycrystalline structures and were found to have compressive stress while the ITO films deposited at higher temperature than 0.99 mTorr was mixture of amorphous and polycrystalline and was found to have tensile stress.

Present Status of Thin Film Solar Cells Using Textured Surfaces: A Brief Review

Hyeongsik Park,SHAIKHMOHAMMAD IFTIQUAR,Anh Huy Tuan Le,Shihyun Ahn,강준영,Yongjun Kim,Junsin Yi,Sunbo Kim,신명훈 한국전기전자재료학회 2016 Transactions on Electrical and Electronic Material Vol.17 No.5

This is a brief review on light trapping in Si based thin film solar cells with textured surfaces and transparentconducting oxide front electrodes. The light trapping scheme appears to be essential in improving device efficiencyover 10%. As light absorption in a thin film solar cells is not sufficient, light trapping becomes necessary to beeffectively implemented with a textured surface. Surface texturing helps in the light trapping, and thereby raises shortcircuit current density and its efficiency. Such a scheme can be adapted to single junction as well as tandem solar cell,amorphous or micro-crystalline devices. A tandem cell is expected to have superior performance in comparison to asingle junction cell and random surface textures appears to be preferable to a periodic structures.

Appropriation of Protocol for Laparoscopic Pancreaticoduodenectomy in Treatment of Periampullary Cancer

( Minh Hai Pham ),( Quan Anh Tuan Le ),( Hoang Bac Nguyen ),( Quang Hung Vu ),( Thai Ngoc Huy Tran ),( Hang Dang Khoa N Guyen ),( Thi Ngoc Sang Duong ),( Van Toan Tran ) 대한간학회 2020 춘·추계 학술대회 (KASL) Vol.2020 No.1

Aims: Laparoscopic pancreaticoduodenectomy (LPD) is considered as a safe and effective procedure in well - selected patients and appropriate surgical technique. Our aim is to evaluate suitability of using protocol for LPD in treatment of periampullary cancer at a single team. Methods: case series Results: Indication for LPD included 37 cases with resectable tumors which were classified basing on NCCN. All witness evaluation risk of complications with PREPARE score, ASA and evaluation risk of postoperative pancreatic fistula (POPF) with FRS classification. There were 2 open conversions because of vein resections, accounting for 5.4%. Standard lymphadenectomy was performed in all of 37 cases. In term of PREPARE score, major complications (Clavien - Dindo >= III) were 17.8%, 0% and 0% (5/28, 0/5 and 0/2 cases) in low risk, intermediate risk and high risk group, respectively. All of cases had ASA I or II. POPF happened 11.1% (1/9), 4.1% (1/24) and 50% (1/2) in low risk, intermediate risk and high risk group, respectively. Frozen section was needed for R0 margin. Retrieved lymph nodes was 8 - 18 with 12 lymph nodes in average. Conclusions: Indication for LPD with resectable tumors is acceptable. ASA I or II is a safe measure to select patient for LPD. FRS classification shows appropriation to evaluate risk of POPF.

Using the light scattering properties of multi-textured AZO films on inverted hemisphere textured glass surface morphologies to improve the efficiency of silicon thin film solar cells

Hussain, Shahzada Qamar,Le, Anh Huy Tuan,Mallem, Kumar,Park, Hyeongsik,Ju, Minkyu,Kim, Yongjun,Cho, Jaehyun,Park, Jinjoo,Kim, Youngkuk,Yi, Junsin Elsevier 2018 APPLIED SURFACE SCIENCE - Vol.447 No.-

<P><B>Abstract</B></P> <P>We report the light scattering characteristics of multi-textured aluminum-doped zinc oxide (AZO) thin films with high optical transmittance, haze ratio and step coverage for amorphous silicon thin film solar cells (a-Si TFSCs). Multi-textured AZO films were deposited on inverted hemisphere textured (IHT) glass surface morphologies. Multi-textured process was used to create modulated surface morphologies with micro and nano-features useful for the light scattering in visible as well as near-infrared wavelength region. Highly transparent IHT glass surface morphologies with high haze ratio were prepared by wet chemical etching of periodic glass substrates. Total transmittance of the IHT glass substrates showed higher average values (91.38–93.40%) as compared to that of bare glass (90.94%) in the visible wavelength region due to lower reflectance. Multi-textured AZO films showed higher rms roughness 100.479 nm, optical transmittance 82.60% and haze ratio 75.09% in the visible wavelength region. X-ray photoelectron spectroscopic analysis of multi-textured AZO thin films was used to study the atomic compositions and chemical binding states. Multi-textured AZO films with high transmittance and haze ratio were used as front transparent conductive oxide layers for the fabrication of a-Si TFSCs using an absorber layer thickness of 400 nm. Multi-textured AZO films deposited on the optimal textured glass surface morphologies yield the maximum performance of a-Si TFSCs as; V<SUB>oc</SUB> = 871 mV, J<SUB>sc</SUB> = 16.55 mA/cm<SUP>2</SUP>, FF = 66.6% and η = 9.61%. An enhancement of photocurrent was noticed from 15.64 to 16.55 mA/cm<SUP>2</SUP> for the a-Si TFSCs deposited on as deposit AZO to optimal textured AZO films.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Micro-featured IHT glass surfaces with high transmittance, haze ratio were prepared. </LI> <LI> Multi-textured AZO films were deposited on IHT glass surface morphologies. </LI> <LI> XPS analysis of AZO films revealed Zn 2p, O 1s and C 1s as the dominating peaks. </LI> <LI> Increase in J<SUB>sc</SUB> upto 16.55 mA/cm<SUP>2</SUP> was related to light scattering in vis-NIR region. </LI> <LI> We propose multi-textured AZO films for future high efficiency silicon TFSCs. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Efficient light trapping for maskless large area randomly textured glass structures with various haze ratios in silicon thin film solar cells

Hussain, Shahzada Qamar,Le, Anh Huy Tuan,Mallem, Kumar,Park, Hyeongsik,Ju, Minkyu,Lee, Sunhwa,Cho, Jaehyun,Lee, Youngseok,Park, Jinjoo,Cho, Eun-Chel,Lee, Youn-Jung,Kim, Youngkuk,Yi, Junsin Elsevier 2018 SOLAR ENERGY -PHOENIX ARIZONA THEN NEW YORK- Vol.173 No.-

<P><B>Abstract</B></P> <P>We report an efficient light trapping for maskless large area randomly textured glass structures with various haze ratios in silicon thin film solar cells. By well controlling the ratio of buffered hydrofluric acid (BHF) and sulfuric acid (H<SUB>2</SUB>SO<SUB>4</SUB>), we were able to prepare the randomly textured maskless glass structures with high transmittance above 90% and variable haze ratio from 20.79 to 54.78% in the visible wavelength (380–800 nm) region. It was observed that haze ratio of textured glass was dependent on feature size, etching depth and rms roughness. Multi-textured aluminum-doped zinc oxide (AZO) films were deposited on textured glass structures showed high transmittance (83.78–85.06)% and haze ratio (45.03–65.05)% in visible wavelength region. An enhancement in haze ratio of multi-textured AZO films was due to an increase of rms roughness from 16.4 to 185.5 nm as shown by 3D-alpha step profiler images. Multi-textured AZO films deposited on various textured glass superstrates were employed as a front transparent conductive oxide (TCO) layer for the fabrication of amorphous silicon (a-Si) thin film solar cells (TFSCs). The a-Si TFSCs deposited on structure-C glass showed the maximum performance as; open circuit voltage = 869 mV, short circuit current density = 16.68 mA/cm<SUP>2</SUP>, fill factor = 67.8% and efficiency = 9.79%. An enhancement of photocurrent was noticed from 15.64 to 16.68 mA/cm<SUP>2</SUP> for as deposited a-Si TFSCs to structure-C based a-Si TFSCs.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Maskless textured glass structures with high transmittance and variable haze ratio are prepared. </LI> <LI> Multi-textured AZO films showed high transmittance, variable haze ratio and modulated surfaces. </LI> <LI> Haze ratio of textured glass was dependent on feature size, etching depth and rms roughness. </LI> <LI> Enhancement of J<SUB>sc</SUB> in a-Si TFSCs upto 16.68 mA/cm<SUP>2</SUP> was related to light trapping invis-NIR wavelength region. </LI> <LI> We propose maskless textured glass with variable haze ratio for future high efficiency Si TFSCs. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>