Effect of the Interaction between Formamidinium Lead Iodine and PbS Quantum Dots in the Black Perovskite Phase Formation and Stability

Formamidinium lead iodine (FAPbI
₃
) is the most appealing material for the fabrication of 3D perovskite solar cells (PSCs), due to the fact of its lower band gap in comparison with the first 3D halide perovskite investigated for photovoltaic applications, the methylammonium lead iodine. However, the crystalline perovskite black phase required for high performing devices is not the most stable phase of FAPbI3 at room temperature, where the non-optically active orthorhombic yellow phase is the stable structure. Here we analyze the effect of the addition of embedded PbS quantum dots (QDs) in FAPbI
₃
matrix regarding the improvement of the black perovskite phase stability of FAPbI
₃
, in terms of QD size.