Photon management in ultra-thin perovskite solar cells using 1D diffraction gratings

Recent advances in perovskite solar cells (PSCs) have demonstrated their potential for low-cost, flexible, and highly efficient photovoltaic applications. However, decreasing the thickness of the active layer poses challenges for maintaining strong optical absorption, making effective photon management crucial. In this work, photon management in PSCs is investigated using one-dimensional multilayer front and rear diffraction gratings. Three-dimensional finite element optical simulations are employed to systematically evaluate the impact of different grating configurations on light coupling and absorption. Angular analysis under both TE and TM polarizations further demonstrates a strong photocurrent response up to an incidence angle of 60°, with greater angular stability under TM-polarized illumination. Compared to Reference cells , the optimized grating-based designs significantly enhance optical performance. For the reference thickness configuration ( h S = 250 nm and h F = 150 nm), the optical photocurrent density ( J Ph ) increases from 20.67 mA/cm 2 to 22.47 mA/cm 2 , corresponding to an enhancement of 8.71 %. For a reduced-thickness design ( h S = 70 nm and h F = 100 nm), the optimized dual-grating structure achieves a J Ph of 23.13 mA/cm 2 , representing a 11.9 % improvement over its planar counterpart. These results demonstrate that properly engineered one-dimensional diffraction gratings can effectively enhance light trapping and enable high-performance PSCs with reduced active material usage.