Performance Enhancement of Solar Cell by Incorporating Bilayer RGO‐ITO Smart Conducting Antireflection Coating

Abstract

Multilayered graphene deposited on a flat resistive surface has twofold benefits. Less electronic scattering reduces the sheet resistance of the combined bilayer and high photon scattering through the unavoidable wrinkles on the chemically synthesized graphene layer leads to decreased effective reflection. In this paper, wet‐chemically‐synthesized reduced graphene oxide (RGO) has been employed on the top of the indium‐doped tin‐oxide (ITO) layer. The ITO layer of optimized thickness has been deposited as an alternative antireflection coating (ARC) on a p/n junction based crystalline silicon solar cell with standard textured surface. Variation in spectral response has been studied experimentally for different thickness and surface coverage of RGO on ITO. The combined effect of reduced sheet resistance due to high surface conductivity and increased photon injection efficiency due to scattering from the wrinkles of RGO results in significant improvement in the performance of the solar cell. By employing optimum thickness of RGO, percentage enhancements of about 18% and 10%, respectively, in efficiency and short‐circuit current density have been achieved over the baseline cell structure. RGO also exhibits an additional benefit as a moisture repelling layer.

Outstanding Room-Temperature Hydrogen Gas Detection by Plasma-Assisted and Graphene-Functionalized Core–Shell Assembly of SnO2 Nanoburflower

“…The Debye length L D for a semiconducting material could be calculated as 2 where “ k B ” is the Boltzmann constant; “ε” is the dielectric constant = ε o × ε r , where “ε r ” is the relative permittivity = ε/ε o ; “ε o ” is the permittivity of free space; “ T ” is the operating temperature in Kelvin scale; “ e ” is the electron charge (1.6 × 10 –19 C); and “ n d ” is the carrier concentration. 53,54 It has been estimated by the researchers that L D for SnO 2 is 3 nm with ε = 13.5, ε o = 8.85 × 10 –12 F/m, and n d = 3.6 × 10 24 m –3 . 3,8,25,53 Therefore, when the SnO 2 particle size is reduced to a size that is comparable to or lower than 2 L D , i.e., 6 nm, the whole crystallite will be fully depleted of electrons, which in turn causes the gas response of the element to change dramatically with D .…”

“…The prominent effect of “nano” size, however, is associated with the thickness of the electron-depleted surface layer, which is defined as the Debye length “ L D ”. The Debye length L D for a semiconducting material could be calculated as where “ k B ” is the Boltzmann constant; “ε” is the dielectric constant = ε o × ε r , where “ε r ” is the relative permittivity = ε/ε o ; “ε o ” is the permittivity of free space; “ T ” is the operating temperature in Kelvin scale; “ e ” is the electron charge (1.6 × 10 –19 C); and “ n d ” is the carrier concentration. , It has been estimated by the researchers that L D for SnO 2 is 3 nm with ε = 13.5, ε o = 8.85 × 10 –12 F/m, and n d = 3.6 × 10 24 m –3 . ,,, Therefore, when the SnO 2 particle size is reduced to a size that is comparable to or lower than 2 L D , i.e., 6 nm, the whole crystallite will be fully depleted of electrons, which in turn causes the gas response of the element to change dramatically with D . Since L D for S10 sample is found to be 2.76 nm (overgrowth diameter), which is much lower than the critical size at which SnO 2 could exhibit the “size-related nanoeffect”, its gas sensing response pitched to its highest level.…”

Recent Advancements in Applications of Graphene to Attain Next-Level Solar Cells

“…Firstly, it reduces electronic scattering thereby, decreasing sheet resistance up to 350 Ω/cm. And secondly, it increases photon scattering at surface wrinkles thereby, decreasing effective reflectance [51].…”

Novel nanocomposites: relationship between microstructure-properties and tribological behavior

“…También se ha probado en forma de óxido de grafeno reducido (rGO), como película protectora y anti reflejante sobre nuevas placas solares, mejorando la eficiencia energética y actuando al mismo tiempo como aislantes contra la humedad [128], o como material alternativo al platino en los electrodos de placas solares [129].…”