Improving the light absorption efficiency in thin-film plasmonic tandem solar cell

Abstract

Recently, thin-film solar cells have received much attention due to low production cost. However, such cells suffer from low efficiency due to which they cannot be used for practical applications. To cater this problem, we have numerically investigated thin-film tandem solar cells comprising of double active layers made of amorphous silicon (a-Si) and crystalline silicon (c-Si) of different energy bandgaps. The tandem cell is found to absorb large amount of solar photons compared to a single a-Si and c-Si solar cells. To further improve the absorption efficiency, we efficiently utilized the surface plasmon resonance (SPR) effect of plasmonic nanoparticles, which are deposited in the form of a square lattice in the top a-Si active layer. The absorption characteristics of the cell are enhanced and tuned by optimizing the material and size of the nanoparticles. Moreover, periodic disorders are incorporated, which allow mixing of plasmonic modes having different angular momenta, resulting in a super broadband light absorption from 300 to 1100 nm and yielding a short circuit current density of 33.917 mA/cm2 in the active layers. The proposed plasmonic tandem cell can be advantageous for most of the photovoltaic applications.