Solar cell design using graphene-based hollow nano-pillars

Abstract

In this paper, the full solar spectrum coverage with an absorption efficiency above 96% is attained by shell-shaped graphene-based hollow nano-pillars on top of the refractory metal substrate. The material choice guarantees the high thermal stability of the device along with its robustness against harsh environmental conditions. To design the structure, constitutive parameters of graphene material in the desired frequency range are investigated and its absorption capability is illustrated by calculating the attenuation constant of the electromagnetic wave. It is observed that broadband absorption is a consequence of wideband retrieved surface impedance matching with the free-space intrinsic impedance due to the tapered geometry. Moreover, the azimuthal and longitudinal cavity resonances with different orders are exhibited for a better understanding of the underlying wideband absorption mechanism. Importantly, the device can tolerate the oblique incidence in a wide span around 65°, regardless of the polarization. The proposed structure can be realized by large-area fabrication techniques.

Review on Theoretical Models of Void Evolution in Crystalline Particles

“…Determined by high specific area and surface-tovolume ratio, low density and encapsulate option, hollow structures exhibit higher performance than their solid counterparts with the same composition and size that tremendously extends their application in the fields of plasmonics [3][4][5], catalysis [6][7][8][9][10][11], energy storing [12][13][14][15] and medicine [16][17][18]. For instance, hollow metal nanoparticles have significantly higher plasmonic properties than their solid counterparts due to so-called mechanism of plasmon hybridization.…”

“…13a, in the cases of SCPs 1 (α 0) = and IcPs 1 (α 0), > the vacancy concentration at the inner and outer surfaces satisfies the Gibbs-Thompson conditions [see Eqs. (10)]. Besides, in the latter case, a local increase of vacancy concentration occurs in vicinity of the void surface -the less is the value of 1 α the higher is the concentration value and the closer the peak position to the void surface.…”

Zwitterionic Bergman cyclization triggered polymerization gives access to metal-graphene nanoribbons using a boron metal couple

“…As we reach the quantum limit of silicon-based semiconductors, graphene-based materials have become the focus of intense research due to their applications in solar cells 1 , 2 , OLEDs 3 , bioengineering 4 , 5 , drug and gene delivery systems 6 , 7 , composite materials 8 , and energy storage devices 9 , 10 . Despite their extraordinary mechanical and optoelectronic properties, vanishing bandgaps in graphene limits its ability to replace silicon-based semiconductors.…”

Zwitterionic Bergman-Triggered Cascade Polymerization: A Plateau Reaction Leading to Metal-Graphene Nanoribbon Semiconductors Using Boron-Metal Couple

“…As we approach the quantum limit of silicon-based semiconductors, the discovery of unique electronic properties of graphene offered a lucrative alternative. In recent years, graphene-based materials have been the focus of intense research due to their application in solar cells, 1,2 organic light emitting diodes (OLEDs), 3 bioengineering, 4,5 drug and gene delivery system, 6,7 composite materials, 8 and energy storage devices. 9,10 However, despite the extraordinary mechanical and optoelectronic properties, the vanishing bandgaps in graphenes limit their scope to replace the silicon-based semiconductors.…”

“…An experimental study by Roth et al in 1994 corroborated the high activation enthalpy of 28.7 ± 0.5 kcal/mol at 200 o C as predicted by Bergman in early 1970s (H # = 32 kcal/mol; HR = 18 kcal/mol). 21,22,23 This is because, unlike concerted pericyclic process, the number of bonds broken (2) and formed (1) in the cycloaromatization step are not conserved, and the conversion of two -bonds into one -bond leads to the formation of a six-membered aromatic diradical that is orthogonal to the aromatic system, and cannot take advantage of adjacent conjugated system (Figure 2, top left). As a result, this diradical is highly reactive and capable of producing variety of fused cycloaromatic compounds.…”