WoS İndeksli Yayınlar Koleksiyonu
Permanent URI for this collectionhttps://hdl.handle.net/20.500.12573/394
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Article Citation - WoS: 4Citation - Scopus: 3Hemispherical-Shell Organic Photovoltaic Cells for Absorption Enhancement and Improved Angular Coverage(SPIE - Society of Photo-Optical Instrumentation Engineers, 2024-02-14) Hah, DooyoungA hemispherical shell shape is proposed for an organic photovoltaic cell structure, aiming at enhancing both light absorption and angular coverage. Three-dimensional finite element analysis method is used to study the absorption spectra within the hemispherical-shell-shaped active layer. The study reveals that the proposed structure can result in 66% and 36% of absorption improvements compared to a flat-structured device when the incoming light is transverse electric (TE)- and transverse magnetic (TM)-polarized, respectively. It is also learned that the proposed hemispherical shell structure has absorption improvement as high as 13% (TE) and 21% (TM) when compared to the previously reported semicylindrical shell structure. The angular coverage of the proposed structure is improved as well, reaching 81 deg (TE) and 82 deg (TM), which becomes quite useful for the wearable electronics applications where the incidence angle can vary in a random manner. These improvements can be attributed to better light coupling and guiding through the active layer made possible by the hemispherical shell shape of the device. (c) 2024 Society of Photo-Optical Instrumentation Engineers (SPIE)Article Citation - WoS: 3Citation - Scopus: 4Clinical Probe Utilizing Surface Enhanced Raman Scattering(A V S Amer Inst Physics, 2014-09-26) Kim, Jeonghwan; Hah, Dooyoung; Daniels-Race, Theda; Feldman, MartinConventional Raman scattering is a well-known technique for detecting and identifying complex molecular samples. In surface enhanced Raman scattering, a nanorough metallic surface close to the sample enormously enhances the Raman signal. In previous work, the metallic surface was a thin layer of gold deposited on a rough transparent epoxy substrate. The advantage of the clear substrate was that the Raman signal could be obtained by passing light through the substrate, on to opaque samples simply placed against its surface. In this work, a commercially available Raman spectrometer was coupled to a distant probe. Raman signals were obtained from the surface, and from the interior, of a solid specimen located more than 1 m away from the spectrometer. The practical advantage of this arrangement is that it opens up surface enhanced Raman spectrometry to a clinical environment, with a patient simply sitting or lying near the spectrometer. (C) 2014 American Vacuum Society.