Strategy for tailoring the size distribution of nanospheres to optimize rough backreflectors of solar cells

Abstract

Abstract:We study the light-trapping properties of surface textures generated by a bottomup approach, which utilizes monolayers of densely deposited nanospheres as a template. We demonstrate that just allowing placement disorder in monolayers from identical nanospheres can already lead to a significant boost in light-trapping capabilities. Further absorption enhancement can be obtained by involving an additional nanosphere size species. We show that the Power Spectral Density provides limited correspondence to the diffraction pattern and in turn to the short-circuit current density enhancement for large texture modulations. However, in predicting the optimal nanosphere size distribution, we demonstrate that full-wave simulations of just a c-Si semi-infinite halfspace at a single wavelength in the range where light trapping is of main importance is sufficient to provide an excellent estimate. The envisioned bottom-up approach can thus reliably provide good light-trapping surface textures even with simple nanosphere monolayer templates defined by a limited number of control parameters: two nanosphere radii and their occurrence probability.

Light‐Trapping Front Textures for Solar Cells from Tailored Mixtures of Nanospheres: A Numerical Study

“…This radial enhancement mimics the isotropic growth process of the ALD layer. The resulting height profile was previously already analyzed for the purpose of being used as a metallic back reflector in solar cells . Here, we add another crucial step: the height profile is taken as the inverse of the nanosphere monolayer.…”

“…The resulting height profile was previously already analyzed for the purpose of being used as a metallic back reflector in solar cells. [29] Here, we add another crucial step: the height profile is taken as the inverse of the nanosphere monolayer. With this, the finer texture features with smaller radii of curvature are more exposed.…”

Tailoring of Silver Nanoparticle Size Distributions in Hydrogenated Amorphous Diamond‐Like Carbon Nanocomposite Thin Films by Direct Femtosecond Laser Interference Patterning

“…[29,30] Tailored nanostructures are also very promising materials for the enhancement of the efficiency of solar cells via light trapping and plasmonic scattering mechanisms. [31,32] In this work, we demonstrate an application of DLIP for the fabrication of 1D periodic structures with subwavelength features in amorphous hydrogenated DLC (a-C:H, further in the text DLC) nanocomposite thin films with embedded silver nanoparticles (DLC:Ag, 7.9-14.1 at% Ag). We have varied the energy densities (laser fluence Φ ¼ 1-145 mJ cm À2 , number of pulses N ¼ 1000-125 000) of ytterbium doped potassium gadolinium tungstate (Yb:KGW) femtosecond-laser second harmonic irradiation to determine ablation and patterning thresholds, and have analyzed incubation effects together with the resulting modifications of silver nanoparticle's effective diameter size distributions.…”

“…The arrangement of nanoparticles in diffraction grating‐like periodic structures modifies the effective refractive index and alters the diffraction efficiency of the periodic structure, which is required to be as high as possible for the most optical applications, especially for increased sensitivity of plasmonic diffractive optical sensors and resonator structures . Tailored nanostructures are also very promising materials for the enhancement of the efficiency of solar cells via light trapping and plasmonic scattering mechanisms …”

Perturbing beyond the shallow amplitude regime: Green’s function scattering formalism with Bloch modes

“…Having on-demand large-area interfaces with desired light interaction is a long-standing vision in the field of optics. Such interfaces have a plethora of applications for various optoelectronic devices, such as solar cells or OLEDs [1][2][3] . For many of these applications, not only that the interfaces should operate optimally in providing a desired scattering response, they should also operate either over an extended spectral domain or with a wide acceptance angle.…”