Light absorption enhancement in ultrathin perovskite solar cells using plasmonic light trapping and bionic anti-reflection coating

Perovskite solar cells have attracted much attention due to their easy fabrication, low cost, and high photoelectric conversion efficiency. To reduce pollution, the absorption layer thickness of perovskite solar cells should be reduced. Moreover, the ultrathin layer can effectively depress the electron–hole recombination in the process of carrier transfer. However, the light absorption of the ultrathin perovskite solar cell is not satisfactory. The promising pathways to design absorption-enhanced ultrathin perovskite solar cells are plasmonic light trapping and anti-reflection coating. In this paper, we propose a design for the light absorption enhancement of ultrathin solar cells with a 100 nm perovskite layer through the integration of plasmonic structure arrays and moth-eye textured anti-reflection coatings. Due to the plasmonic scattering and the antireflection effect, an optimized light absorption enhancement of 41% has been achieved, compared with a 100 nm blank layer. In this case, a silver cylindrical array with a radius of 100 nm, a height of 120 nm, and a coverage of 12% is embedded into the rear-side hole transport layer. Inverted pyramids of the moth-eye textures with a base length of 180 nm and a depth of 125 nm are located on the front surface of the antireflection coating and further improve the perovskite light absorption. The absorbance of the 100 nm layer is dramatically raised to 72.51%, which is comparable to that of a 300 nm perovskite layer (72.86%). The simulation results pave the way for the realization of environmental-friendly and high-performance perovskite optoelectronic devices.