• Title/Summary/Keyword: Boundary shifting

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High-k ZrO2 Enhanced Localized Surface Plasmon Resonance for Application to Thin Film Silicon Solar Cells

  • Li, Hua-Min;Zang, Gang;Yang, Cheng;Lim, Yeong-Dae;Shen, Tian-Zi;Yoo, Won-Jong;Park, Young-Jun;Lim, Jong-Min
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.276-276
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    • 2010
  • Localized surface plasmon resonance (LSPR) has been explored recently as a promising approach to increase energy conversion efficiency in photovoltaic devices, particularly for thin film hydrogenated amorphous silicon (a-Si:H) solar cells. The LSPR is frequently excited via an electromagnetic (EM) radiation in proximate metallic nanostructures and its primary con sequences are selective photon extinction and local EM enhancement which gives rise to improved photogeneration of electron-hole (e-h) pairs, and consequently increases photocurrent. In this work, high-dielectric-constant (k) $ZrO_2$ (refractive index n=2.22, dielectric constant $\varepsilon=4.93$ at the wavelength of 550 nm) is proposed as spacing layer to enhance the LSPR for application to the thin film silicon solar cells. Compared to excitation of the LSPR using $SiO_2$ (n=1.46, $\varepsilon=2.13$ at the wavelength of 546.1 nm) spacing layer with Au nanoparticles of the radius of 45nm, that using $ZrO_2$ dielectric shows the advantages of(i) ~2.5 times greater polarizability, (ii) ~3.5 times larger scattering cross-section and ~1.5 times larger absorption cross-section, (iii) 4.5% higher transmission coefficient of the same thickness and (iv) 7.8% greater transmitted electric filed intensity at the same depth. All those results are calculated by Mie theory and Fresnel equations, and simulated by finite-difference time-domain (FDTD) calculations with proper boundary conditions. Red-shifting of the LSPR wavelength using high-k $ZrO_2$ dielectric is also observed according to location of the peak and this is consistent with the other's report. Finally, our experimental results show that variation of short-circuit current density ($J_{sc}$) of the LSPR enhanced a-Si:H solar cell by using the $ZrO_2$ spacing layer is 45.4% higher than that using the $SiO_2$ spacing layer, supporting our calculation and theory.

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Return of Self-identity and Story of the Other which disappeared in Advaita Vedanta (아드와이따 베단따의 자아정체성 귀환과 사라진 타자의 이야기)

  • Park, Hyo-yeop
    • Journal of Korean Philosophical Society
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    • v.126
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    • pp.109-132
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    • 2013
  • The most important vocabulary in Advaita $Ved{\bar{a}}nta$, which is anthropology and soteriology on the self, is of course '${\bar{a}}tman$' or 'the self', to which '$an{\bar{a}}tman$' or 'the other' is in opposition. As $Ved{\bar{a}}ntic$ system revolves around the concept ${\bar{a}}tman$, it can be compared favorably with 'final vocabulary' of Richard Rorty. Moreover, $Ved{\bar{a}}ntic$ system can be termed as 'a return of self-identity', in which a process of returning is from a deceived self to the true and original self. After all, story of '$an{\bar{a}}tman$' or 'the other' in $Ved{\bar{a}}nta$ seems to have no significance at all. However, discourse about the other can also lead a something fruitful. There are such doctrines in $Ved{\bar{a}}nta$ that support a procedure of self-realization not according to the Hegelian dialectic but to the transposition and continuous antagonism between the self and the other, as a special meaning of viveka (discrimination) that fixes a boundary between the self and the other, a destruction of falsehood that is more important than establishment of truthfulness, a transposition of the true and the false before and after self-realization. Thus the other is not disappeared but only hidden, even after accomplishing its own methodological role, and the same is with discourse about the other. To revive forgotten vocabulary in $Ved{\bar{a}}nta$ is an attempt to reconstruct devaluated story by means of shifting the pivot of discourse from the self to the other. The essential thing in this attempt may be to revive the conceptions of 'effort' that is intently concealed and of 'self-inquiry' that has lost its true meaning. Out of these, a systematic and continuous self-inquiry, consists in having a scenario on the question 'Who am I?' and utilizing that scenario by experience without interruption. A work of reconstructing the lost narratives in $Ved{\bar{a}}nta$ can be feasible only when the history of self-inquiry is redescribed in the system itself, provided that object of inquiry is not 'a self as the self' but 'a self as the other'.