Refractory plasmonics boost the performance of thin-film solar cells

Abstract

Plasmonic thin-film solar cells have recently gained a great research attention due to the tunability of plasmonic nanoparticles with efficient light trapping characteristics. Although noble metals have shown great optoelectronic properties, they are expensive, rare, and unavailable for large-scale production and integration. Herein, the possibility to replace noble metals with transition metal nitrides/oxynitrides as refractory plasmonic materials is presented through finite-difference-time-domain “FTDT” simulations. Titanium nitride “TiN” promises mass-production on lower-cost as well as abundance relative to noble metals, along with being complementary metal oxide semiconductor “CMOS” process compatible. The similar optoelectrical properties between transition metals and noble metals, such as gold or silver, make this replacement possible, and interesting to investigate. The plasmonic effect of TiN across the scattering and absorption cross-section is simulated, and the results are demonstrated and discussed. Afterwards, the I-V characteristics for a 2 μm thin-film solar cell with TiN nanoparticles with different configurations are presented. Then, multiple sizes of multiple nanostructures are analyzed, simulated, and presented, targeting the closest scattering and coupling-to-substrate efficiency to gold nanoparticles, and hence better overall efficiency.