Simulation and partial prototyping of an eight‐junction holographic spectrum‐splitting photovoltaic module

Abstract

Spectrum‐splitting photovoltaics incorporate optical elements to separate sunlight into frequency bands, which can be targeted at solar cells with bandgaps optimized for each sub‐band. Here, we present the design of a holographic diffraction grating‐based spectrum‐splitting photovoltaic module integrating eight III‐V compound semiconductor cells as four dual‐junction tandems. Four stacks of simple sinusoidal volume phase holographic diffraction gratings each simultaneously split and concentrate sunlight onto cells with bandgaps spanning the solar spectrum. The high‐efficiency cells get an additional performance boost from concentration incorporated using a single or a compound trough concentrator, providing up to 380X total concentration. Cell bandgap optimization incorporated an experimentally derived bandgap‐dependent external radiative efficiency function. Simulations show 33.2% module conversion efficiency is achievable. One grating stack is experimentally fabricated and characterized.

Development of high efficiency and wide acceptance angle holographic solar concentrators for breakthrough photovoltaic applications

“…The prepolymer solution in water is composed of 13.3 w/V poly(vinyl alcohol) (PVA) as inert binder polymer (Mw ∼ 130000), degree of hydrolysis = 87.7%), sodium acrylate (C 3 H 3 NaO 2 ) as polymerizable monomer (Mw ∼ 94.04), triethanolamine (TEA) as coinitiator and plasticizer (Mw = 149. 19) and sodium salt 5'-riboflavin monophosphate (RF) as sensitizing dye (Mw = 478.33). All compounds were purchased from Merck KGaA (Darmstadt, Germany).…”

“…For example, their spectral selectivity allows them to focus each band frequency at a particular diffracted angle or a particular solar PV cell characterized with a singular bandgap. 19,20 Therefore, versatile multiplexed holographic solar concentrators, which foucs sunlight at different incidence angles are presented in this work as a major challenge in solar energy innovation (Figure 3). Here we have studied multiplexed HLs with a short focus distance (f ′ ), around 5 cm.…”

Overview of the Current State of Gallium Arsenide-Based Solar Cells

“… ( A ) Stacks of discrete holographic elements (a single stack is described in part ( C )) generate four spectral bands coupled into one of four dual-junction solar cells, including GaAs. Part ( B ) shows the volume phase hologram of thickness d with fringes representing the refractive index with periodicity L , tilted to the grating normal by angle ϕ, where incident light is split into diffracted orders [ 9 ]. …”

“…Another interesting use of cells was the design of the first holographic diffraction system to incorporate eight solar subcells, more precisely, four different dual-junction PV cells, as can be seen in Figure 1 . Darbe et al declared by simulations 33.2% module conversion efficiency, including external losses, and 63.0% with ideal cells and optics [ 9 ].…”

Effect of plasmonic Aluminum nanoparticles shapes on optical absorption enhancement in silicon thin-film solar cells

“…An ideal solar cell should have four main features: first, having a direct band-gap between 1.1 to 1.7 eV, second, consisting of non-toxic and available material in nature, third, having a high photovoltaic conversion efficiency, and four, to be produced easily for large areas 3,4 . Among all the growing up kinds of solar cells [5][6][7][8][9][10][11] , thinfilm solar cells 3 always have been considered as the low cost one. However, this cost reduction is due to the decrease in the thickness of the active layer, which is mostly made of silicon because of its cost-effective, earth abundance, non-toxicity, and processing availability 12 .…”