%0 Online Multimedia %A Masi, Sofia %A Echeverría-Arrondo, Carlos %A Salim, K. M. Muhammed %A Ngo, Thi Tuyen %A Mendez, P. F. %A López-Fraguas, Eduardo %A Macias-Pinilla, David F. %A Planelles, Josep %A Climente, Juan I. %A Mora-Seró, Iván %D 2020 %T Chemi-Structural Stabilization of Formamidinium Lead Iodide Perovskite by Using Embedded Quantum Dots %U https://acs.figshare.com/articles/media/Chemi-Structural_Stabilization_of_Formamidinium_Lead_Iodide_Perovskite_by_Using_Embedded_Quantum_Dots/11604273 %R 10.1021/acsenergylett.9b02450.s002 %2 https://acs.figshare.com/ndownloader/files/21000321 %K phase %K perovskite %K V oc %K PbS %K efficiency %K QD %K FAPI %K band gap %X The approaches to stabilize the perovskite structure of formamidinium lead iodide (FAPI) commonly result in a blue shift of the band gap, which limits the maximum photoconversion efficiency. Here, we report the use of PbS colloidal quantum dots (QDs) as a stabilizing agent, preserving the original low band gap of 1.5 eV. The surface chemistry of PbS plays a pivotal role by developing strong bonds with the black phase but weak ones with the yellow phase. As a result, a stable perovskite FAPI black phase can be formed at temperatures as low as 85 °C in just 10 min, setting a record of concomitantly fast and low-temperature formation for FAPI, with important consequences for industrialization. FAPI thin films obtained through this procedure reach an open-circuit potential (Voc) of 1.105 V, 91% of the maximum theoretical Voc, and preserve the efficiency for more than 700 h. These findings reveal the potential of strategies exploiting the chemi-structural properties of external additives to relax the tolerance factor and optimize the optoelectronic performance of perovskite materials. %I ACS Publications