Embedded metal nanopatterns as a general scheme for enhanced broadband light absorption

作者：Ye Fan; Burns Michael J; Naughton Michael J^*

来源：Physica Status Solidi A-Applications and Materials Science, 2015, 212(3): 561-565.

DOI：10.1002/pssa.201431544

• broadband enhanced absorption
• embedded metal nanopattern
• metamaterial
• optical impedance match
• plasmonics

Recently, various light trapping schemes based on inclusions of dielectric or metallic nanoparticles or nanopatterns on top of, below, or embedded within a photovoltaic (PV) absorber have been proposed to enhance the efficiency of solar cells. We demonstrate here that embedded metal nanopatterns (EMN) within the absorber layers of thin film solar cells can serve as a general scheme for broadband light absorption enhancement. The EMN scheme is compatible with a wide variety of non-crystalline solar cells, including amorphous, polycrystalline, organic, polymeric, and dye-sensitized solar cells. Simulations on the same EMN in various PV media show consistent absorption enhancement. An impedance matching model is used to explain the robustness of the effect, wherein the EMN brings the impedance of the thin-film solar cell closer to that of free space in a broadband manner, resulting in exceptional absorption enhancement in the near band gap regime. Experimental verifications are provided by Ag connecting network nanopatterns fabricated by nanosphere lithography embedded in an amorphous silicon layer, resulting in a broadband absorbance enhancement, especially in the near band gap region, in good agreement with our predictions.

• 出版日期2015-3