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Skaane P.,University of Oslo | Kshirsagar A.,R2 Technology | Hofvind S.,Institute of Population based Cancer Research | Jahr G.,University of Oslo | Castellino R.A.,R2 Technology
Acta Radiologica | Year: 2012

Background: Double reading improves the cancer detection rate in mammography screening. Single reading with computer-aided detection (CAD) has been considered to be an alternative to double reading. Little is known about the potential benefit of CAD in breast cancer screening with double reading. Purpose: To compare prospective independent double reading of screen-film (SFM) and full-field digital (FFDM) mammography in population-based screening with retrospective standalone CAD performance on the baseline mammograms of the screen-detected cancers and subsequent cancers diagnosed during the follow-up period. Material and Methods: The study had ethics committee approval. A 5-point rating scale for probability of cancer was used for 23,923 (SFM = 16,983; FFDM = 6940) screening mammograms. Of 208 evaluable cancers, 104 were screen-detected and 104 were subsequent (44 interval and 60 next screening round) cancers. Baseline mammograms of subsequent cancers were retrospectively classified in consensus without information about cancer location, histology, or CAD prompting as normal, non-specific minimal signs, significant minimal signs, and false-negatives. The baseline mammograms of the screen-detected cancers and subsequent cancers were evaluated by CAD. Significant minimal signs and false-negatives were considered 'actionable' and potentially diagnosable if correctly prompted by CAD. Results: CAD correctly marked 94% (98/104) of the baseline mammograms of the screen-detected cancers (SFM = 95% [61/64]; FFDM = 93% [37/40]), including 96% (23/24) of those with discordant interpretations. Considering only those baseline examinations of subsequent cancers prospectively interpreted as normal and retrospectively categorized as 'actionable', CAD input at baseline screening had the potential to increase the cancer detection rate from 0.43% to 0.51% (P = 0.13); and to increase cancer detection by 16% ([104 + 17]/104) and decrease interval cancers by 20% (from 44 to 35). Conclusion: CAD may have the potential to increase cancer detection by up to 16%, and to reduce the number of interval cancers by up to 20% in SFM and FFDM screening programs using independent double reading with consensus review. The influence of true- and false-positive CAD marks on decision-making can, however, only be evaluated in a prospective clinical study.


Lee C.-L.,Nation University | Lee W.-H.,Nation University | Li W.-T.,R2 Technology | Yang C.-H.,R2 Technology | Kao P.-C.,National Chiayi University
Materials Research Bulletin | Year: 2013

Efficient flexible dye-sensitized solar cells (DSSCs) using a stainless steel (StSt) substrate for preparing nanocrystalline TiO2 film electrodes were developed. Large active area (>1 cm2) and SiO x/ITO free StSt DSSCs were fabricated for a systematic investigation. As cell area increased from 1 cm2 (device A) to 4 cm2 (device D) the power conversion efficiency dropped significantly, mostly due to a decrease in the fill factor (FF) and suppression of the short-circuit current density (Jsc). By integrating small-area cells onto StSt substrate to fabricate the large-area DSSC (device C), Rsheet-TCO (sheet resistance of the TCO) can be reduced significantly, yielding the improved performance of the DSSCs. Compared with other methods to prepare StSt-based photoelectrodes, such as sputtering, we provide a simple, low cost and suitable method for the large scale preparation of DSSCs. © 2013 Elsevier Ltd. All rights reserved.


Lee C.-L.,Nation University | Lee W.-H.,Nation University | Yang C.-H.,R2 Technology | Yang H.-H.,R2 Technology | Chang J.-Y.,University of Taipei
Materials Research Bulletin | Year: 2013

Triazoloisoquinoline contains electron-rich nitrogen and oxygen heteroatoms in a heterocyclic structure with high electron-donating ability. By utilizing this feature, two organic dyesutffs containing triazoloisoquinoline were synthesized and used in the fabrication of dye-sensitized solar cells (DSSCs), overcoming the deficiency of ruthenium dyestuff absorption in the blue part of the visible spectrum. This method also fills the blanks of ruthenium dyestuff sensitized TiO2 film, and forms a compact insulating molecular layer due to the nature of small molecular organic dyestuffs. The incident photon-to-electron conversion efficiency of N719 at shorter wavelength regions is 35%. After addition of triazoloisoquinoline-based dyestuff for co-sensitization, the IPCE at 350-500 nm increased significantly. This can be attributed to the increased photocurrent of the cells, which improves the dye-sensitized photoelectric conversion efficiency from 4.49% to 5.15%, which the overall conversion efficiency increased by about 15%. As a consequence, this low molecular weight organic dyestuff is a promising candidate as co-adsorbent and co-sensitizer for highly efficient dye-sensitized solar cells. © 2012 Elsevier Ltd.


Dumas C.,CNRS Institute Materials Microelectronics nanosciences of Provence | Deleruyelle D.,CNRS Institute Materials Microelectronics nanosciences of Provence | Demolliens A.,CNRS Institute Materials Microelectronics nanosciences of Provence | Muller C.,CNRS Institute Materials Microelectronics nanosciences of Provence | And 6 more authors.
Thin Solid Films | Year: 2011

This paper demonstrates the feasibility of resistive switching memory elements integrating a nickel oxide film deposited on top of a pillar bottom electrode. The unipolar switching was investigated over a wide temperature range (25 to 125 °C) on samples integrating either W or Cu plugs with diameters ranging from 1 down to 0.18 μm. The switching characteristics and scaling trends of various fabricated memory elements were compared to select the best bottom electrode contact. It was shown that NiO layers deposited on top of W-plugs exhibited the most satisfactory electrical characteristics for future high density memory devices. Their reliability performances in terms of endurance and retention were subsequently studied by using either quasi-static or pulse programming modes. Set operations with short (10 to 20 ns) and low amplitude (around 2 V) voltage pulses were also demonstrated. © 2011 Elsevier B.V. All rights reserved.


Wu B.-L.,National Taiwan University of Science and Technology | Chao H.-J.,National Taiwan University of Science and Technology | Chen C.-P.,Ming Chi University of Technology | Yang C.-H.,R2 Technology | Chang J.-Y.,National Taiwan University of Science and Technology
RSC Advances | Year: 2015

In this work, we present the synthesis of Cdx:CuInS2 quaternary quantum dots (q-QDs) using a one-pot non-injection approach of alloying CuInS2 with Cd2+. Photoluminescence measurements showed that an increase in the Cd mole fraction in Cdx:CuInS2 q-QDs caused a systematic blue-shift in the QD emission wavelength. The as-prepared Cdx:CuInS2 q-QDs exhibited emissions in the range of 560-645 nm, and a maximum fluorescence quantum yield of 22%. Time-resolved photoluminescence measurements indicated that the average lifetime of Cdx:CuInS2 q-QDs became shorter compared to that of the CuInS2 ternary QDs (t-QDs), clearly indicating that a certain amount of Cd2+ defects exist inside the CuInS2 host. The photovoltaic performance of QD-sensitized solar cells (QDSSCs) was investigated by sandwiching a polysulfide electrolyte between Cdx:CuInS2 q-QDs photoanodes and Cu2S photocathodes. A maximum energy conversion efficiency of 1.74% was obtained under AM1.5 G simulated solar light for the cell fabricated with Cdx:CuInS2 q-QDs (x = 1) as the sensitizer, which is about 70% and 35% better than the cells sensitized with pristine CuInS2 t-QDs and Zn:CuInS2 q-QDs, respectively. More interestingly, it was noted that JSC systematically improved as the quantum yields of Cdx:CuInS2 q-QDs increased, resulting in an enhancement in power conversion efficiency. Furthermore, the power conversion efficiency of the solar cells co-sensitized with Cd:CuInS2 and CdSe can be elevated further to an encouraging 2.86%. © 2015 The Royal Society of Chemistry.


Lee C.-L.,Nation University | Lee W.-H.,Nation University | Yang C.-H.,R2 Technology
International Journal of Photoenergy | Year: 2013

The influence of using different concentrations of triazoloisoquinoline based small molecule as coadsorbent to modify the monolayer of a TiO2 semiconductor on the performance of a dye-sensitized solar cell is studied. The co-adsorbent significantly enhances the open-circuit photovoltage (Voc), the short circuit photocurrent density (Jsc) the solar energy conversion efficiency (>η). The co-adsorbent 4L is applied successfully to prepare an insulating molecular layer with N719 and achieve high energy conversion efficiency as high as 8.83% at 100 mW cm-2 and AM 1.5 at 1 to 0.25 (N719: co-adsorbent) molar ratio. The resulting efficiency is about 6% higher than that of a nonadditive device. The result shows that the organic small molecule 4L (2-cyano-3-(5-(4-(3-oxo-[1,2,4]triazolo[3,4-a]isoquinoline-2(3H)-yl) phenyl)thiophene-2-yl)acrylic acid) is the promising candidates for improvement of the performance of dye-sensitized solar cell. © 2013 Che-Lung Lee et al.


Lee C.-L.,Nation University | Lee W.-H.,Nation University | Yang C.-H.,R2 Technology
Journal of Materials Science | Year: 2013

Triazoloisoquinoline-based organic dyestuff was synthesized and used in the fabrication of dye-sensitized solar cells (DSSCs). After co-sensitization with ruthenium complex, triazoloisoquinoline-based organic dyestuff overcomes the deficiency of ruthenium dyestuff absorption in the blue part of the visible spectrum. The incident photon-to-electron conversion efficiency (IPCE) of cis-dithiocyanate-N,N′-bis-(4-carboxylate-4-tetrabutyl ammoniumcarboxylate-2,2′-bipyridine)ruthenium(II) (N719) at shorter wavelength regions (~350-500 nm) is 35 %. After addition of triazoloisoquinoline-based dyestuff for co-sensitization, the IPCE at 350-500 nm increased significantly. This can be attributed to the increased photocurrent of the cells, which improves the dye-sensitized photoelectric conversion efficiency. After optimization of the cells, an energy conversion efficiency of 8.83 % was achieved using an 12 + 4 μm TiO2 electrode, under simulated solar illumination (AM 1.5G). As a consequence, this low molecular weight organic dyestuff is a promising candidate as a co-adsorbent and co-sensitizer for highly efficient DSSCs. © 2013 Springer Science+Business Media New York.


Shimada T.,R2 Technology | Koyama F.,R2 Technology
Conference Program - MOC'11: 17th Microoptics Conference | Year: 2011

We demonstrate the lateral integration of a VCSEL and a slow light amplifier. We realized the loss compensation and amplification for a compact slow light amplifier laterally integrated with a VCSEL. The integration enables us to increase the single-mode output power of VCSELs. © 2011 The Japan Society of Applied Physics.


Mazzone G.,R2 Technology | Bano G.,R2 Technology | Gianni D.M.,R2 Technology | Castelletti L.,R2 Technology | Borsari S.,R2 Technology
IEEE Transactions on Semiconductor Manufacturing | Year: 2013

The measurement of the light reflected by the surface of the wafer during process is one of the most widely used endpoint detection methods for the chemical mechanical polishing of metals. In spite of the many advantages in the process, the endpoint traces are seen just as a drop in reflectivity that marks the end of the process. In this paper, we analyze the optical endpoint traces commonly obtained during tungsten CMP and we focus our attention on different features that characterize the curve shape. Using both measurements and theoretical simulations of reflectivity of the film stack involved, we describe such characteristics and connect them to the layers being polished and to the lifetime of CMP pad installed on the equipment. In particular, we focus on a secondary peak of intensity that can be seen when the thickness of titanium nitride under tungsten increases, and on the darkening of pad window as the lifetime increases. Finally, we simulate the endpoint traces by using internal library values of optical properties of materials involved, achieving a good match between real and simulated curve. © 1988-2012 IEEE.


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