Over 65% Sunlight Absorption in a 1 μm Si Slab with Hyperuniform Texture

Abstract

Thin, flexible, and invisible solar cells will be a ubiquitous technology in the near future. Ultrathin crystalline silicon (c-Si) cells capitalize on the success of bulk silicon cells while being lightweight and mechanically flexible, but suffer from poor absorption and efficiency. Here we present a new family of surface texturing, based on correlated disordered hyperuniform patterns, capable of efficiently coupling the incident spectrum into the silicon slab optical modes. We experimentally demonstrate 66.5% solar light absorption in free-standing 1 μm c-Si layers by hyperuniform nanostructuring for the spectral range of 400 to 1050 nm. The absorption equivalent photocurrent derived from our measurements is 26.3 mA/cm 2 , which is far above the highest found in literature for Si of similar thickness. Considering state-of-the-art Si PV technologies, we estimate that the enhanced light trapping can result in a cell efficiency above 15%. The light absorption can potentially be increased up to 33.8 mA/cm 2 by incorporating a back-reflector and improved antireflection, for which we estimate a photovoltaic efficiency above 21% for 1 μm thick Si cells.

Evolving scattering networks for engineering disorder

“…The suggested network model characterizes wave scattering as the network depending on the length scale of interest, which is suitable for designing materials with unique length-scale-dependent natures. As a representative example, I develop the evolution process towards stealthy hyperuniformity (SHU), which indicates the structural characteristics from the bounded suppression of density fluctuations at long-range scales 32,[36][37][38][39] and has been studied in numerous natural or engineered systems, such as cosmological models 40 , avian photoreceptors 41 , amorphous silica 42 , space partitioning 43 , prime numbers 44 , bandgap materials 31,45,46 and sunlight absorbers 47 . The proposed evolution process enables the network-based classification of material phases and the screening of existing materials with SHU states.…”

Nanopatterned SiNx Broadband Antireflection Coating for Planar Silicon Solar Cells

“…Recent work has investigated nanopatterned [ 19 ] and multilayer AR coatings [ 20 ] to effectively couple light into the solar cell and, in some cases, preferentially redirect light into angular channels at which light is trapped by total internal reflection within the absorber. [ 21–25 ]…”

“…Recent work has investigated nanopatterned [19] and multilayer AR coatings [20] to effectively couple light into the solar cell and, in some cases, preferentially redirect light into angular channels at which light is trapped by total internal reflection within the absorber. [21][22][23][24][25] Here, we introduce a single-layer periodic nanopattern of SiN x disks combined with a planar SiN x layer on the planar front DOI: 10.1002/pssa.202200827 Crystalline Si solar cells based on thin wafers, with thicknesses in the range of 5-50 μm, can find applications in a wide range of markets where flexibility and bendability are important. For these cells, avoiding standard macroscopic texture is desirable to increase structural integrity.…”

Local order metrics for two-phase media across length scales*

“…The large-R behavior of σ 2 V (R) is at the heart of the hyperuniformity concept. Hyperuniform two-phase media are characterized by an anomalous suppression of volume-fraction fluctuations relative to garden-variety disordered media [22,24] and can be endowed with novel properties [9,19,24,[27][28][29][30][31][32][33][34][35][36][37][38][39][40][41]. Specifically, a hyperuniform two-phase system is one in which σ 2…”