The addition of organic cationic iodides to form low-dimensional perovskite is an essential strategy for defect passivation in perovskite solar cells (PSCs). Specially, the 2D/3D perovskite structure can combine the stability of 2D perovskite and the high charge transport performance of 3D perovskite. Here, we introduced phenylammonium hydroiodide salts with different alkyl chain lengths into PSCs precursor solution to research the influence on formation of perovskite thin films and the photovoltaic performance of PSCs. As a result, the champion power conversion efficiency (PCE) of PSCs was increased to 22.68% by incorporation of the organic cation phenylpropyl ammonium iodide (PPAI) with the best alkyl chain length. We further fabricated the perovskite solar modules (PSMs) with an aperture area of 21 cm2, achieving an impressive efficiency of 21.65% with excellent stability that maintaining 89% of its initial efficiency after 1000 h of maximum power point tracking.
Keywords: 2D/3D structure; alkyl chain length; efficiency; organic cation additives; perovskite solar cells; stability.