Enhanced photon trapping in perovskite solar cells via grating structures

Insufficient light absorption and weak environmental stability are important issues that hinder the development of perovskite solar cells (PSCs). This Letter reports a structurally engineered photon management strategy utilizing a corrugated electron transport layer for enhanced photon trapping in PSCs. The synergistic interplay of grating-induced scattering and diffraction effects leads to a broadband absorption enhancement spanning 300-800 nm in the perovskite layer. When the period of the grating structure is 1.5 μm, the absorption of the perovskite layer reaches its maximum value, and the J_SC of the PSC is increased from 23.00 mA/cm² of the flat device to 24.97 mA/cm². Moreover, due to the hydrophobic effect of the grating structure, the humidity stability of the PSCs has also been improved. After being stored in nitrogen at 30% relative humidity (RH) and 20°C for 120 h, the PCE drops to 89.8% of the initial value.