Design of plasmonic back structures for efficiency enhancement of thin-film amorphous Si solar cells

Abstract

Metallic back structures with one-dimensional periodic nanoridges attached to a thin-film amorphous Si (a-Si) solar cell are numerically studied. At the interfaces between a-Si and metal materials, the excitation of surface-plasmon polaritons leads to obvious absorption enhancements in a wide near-IR range for different ridge shapes and periods. The highest enhancement factor of the cell external quantum efficiency is estimated to be 3.32. The optimized structure can achieve an increase of 17.12% in the cell efficiency.

Angle insensitive enhancement of organic solar cells using metallic gratings

“…The chosen metal back contact material is silver, as it allows for low metal absorption losses, and beneficial SPP resonance wavelengths. An example of the usage of silver square gratings to enhance silicon thin film solar cells is shown in recent publications [12,15]. Here, we explore the characteristics further and we examine specifically the angular behaviour of the excited modes for bulk heterojunction solar cells made of P3HT:PCBM (poly(3-hexylthiophene): [6,6]-phenyl-C61-butyric acid methyl ester) blends.…”

“…Several metal geometries (gratings, particles [6][7][8][9]) and their locations in the cell (front, middle or back) are under active investigation for different types of solar cells. Plasmonic grating structures [5,[10][11][12][13][14][15] form a particularly interesting class, as they involve the patterning of an available metallic electrode.…”

Volumetric plasmonic resonator architecture for thin-film solar cells

“…[3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] These prior studies used either randomly distributed metal nanoparticles 3,6,7 or nanopatterned metal layers. 3,[8][9][10][11][12][13][14] Although such metal nanoparticles can be conveniently blended across the active layers, they suffer from random distribution in the active material and limited spatial control. On the other hand, the metal layers can be nanostructured with precision.…”

“…But these use only a single nanopatterned layer of plasmonic structures, which limits the full utilization of the volume of the active material. All of these previous designs were based on placing the metal layer either only on the top 3,[7][8][9][10]15 or only at the bottom 3,[11][12][13][14] of the active layers for exciting their plasmon modes. The resulted absorption enhancement levels reported for such single layers have typically been limited within the range of ϳ18% -50%, when considering both transverse-magnetic ͑TM͒ and transverse-electric ͑TE͒ polarizations.…”

“…The resulted absorption enhancement levels reported for such single layers have typically been limited within the range of ϳ18% -50%, when considering both transverse-magnetic ͑TM͒ and transverse-electric ͑TE͒ polarizations. 8,9,12,13 Therefore, there is a need for further extending field localization across the volume of the active materials to contribute to increasing field localization and enhancing photon absorption efficiency in thin-film solar cells, beyond the improvement levels obtained using individual plasmonic layers. This, however, requires innovative designs.…”