Enhanced light absorption of organic solar cells based on stopped-trench metal grating

Here, the influence of dimensional parameters of the trench metal grating on the absorption efficiency of organic solar cells (OSCs) was evaluated. The plasmonic modes were calculated. Due to the capacitance-like charge distribution in a plasmonic configuration, the platform width of grating has a significant influence on the intensity of wedge plasmon polaritons (WPPs) and Gap surface plasmon (GSPs). Stopped-trench gratings would lead to better absorption efficiency than thorough-trenched gratings. The stopped-trench gratings (STG) model with a coating layer showed 77.01% integrated absorption efficiency, which is 19.6% better than previously reported works with 19% less photoactive materials. This model offered 18% integrated absorption efficiency, better than an equivalent planar structure without a coating layer. Specifying the areas with maximum generation on the structure helps us to manage and reduce the thickness and volume of the active layer to control the recombination losses and the cost. We rounded the edges and corners with a curvature radius of 30 nm to investigate tolerance during fabrication. Results demonstrated that the integrated absorption efficiency profile of the blunt model is slightly different from the integrated absorption efficiency profile of the sharp model. Finally, we have studied the wave impedance (Zx) inside the structure. Between the spectrum of lambda =similar to 700 nm to lambda=900 nm, an extremely high wave impedance layer was formed. It creates an impedance mismatch between layers and helps us to better trap the incident light ray. STG with a coating layer (STGC) is a promising way to produce OCSs with extremely thin active layers.

Automated summary

This study evaluated the influence of dimensional parameters of trench metal grating on the absorption efficiency of organic solar cells (OSCs) and calculated the plasmonic modes. The width of the grating platform significantly affected the intensity of wedge plasmon polaritons (WPPs) and Gap surface plasmon (GSPs) due to the charge distribution in a plasmonic configuration. Stopped-trench gratings showed better absorption efficiency than thorough-trenched gratings. A stopped-trench gratings model with a coating layer exhibited 77.01% integrated absorption efficiency, outperforming previous works with 19% less photoactive materials.