Large-Area Perovskite Solar Modules Based on Uniformity Engineering of Perovskite Films: The Critical Role of Methyldiphenylphosphine Oxide Additive.

ABSTRACT

Perovskite solar cells (PSCs) have led to distinguished achievements and become one of the state-of-the-art photovoltaic technologies. Undoubtedly, reliable preparation of large area high-quality perovskite (PVK) films with uniform optoelectronic properties has become a critical and challenging task to transition PSCs from lab to market. Here, methyldiphenylphosphine oxide (MDPPO) is employed as an additive in a PVK precursor solution to promote uniform conductivity and carrier transport of PVK films. More important, to check its compatibility with the upscaling process, the MDPPO additive strategy was further applied to doctor-blade large-area PVK films. As a result, benefit from the favorable role of MDPPO additive, the power conversion efficiencies (PCEs) of small-area PSCs reach 23.85% with superb open circuit voltage (Voc) of 1.15 V and fill factor of 81.21%, while an impressive PCE of 19.22% was achieved for the large-area PSC minimodules with active area of 61.48 cm2. Remarkably, the MDPPO modified device exhibits significantly improved operational stability, maintaining an initial efficiency of 68% even after 750 h under continuous 1-sun illumination. Our achievements will provide profound insight and further guidance for the scale-up process of PSCs from lab to large-scale modules.