Unveiling of a puzzling dual ionic migration in lead- and iodide-deficient halide perovskites (d-HPs) and its impact on solar cell curve hysteresis.

Halide perovskite solar cells are characterized by a hysteresis between current-voltage (- curves recorded on the reverse and on the forward scan directions, and the suppression of this phenomenon has focused great attention. In the present work, it is shown that a special family of 3D perovskites, that are rendered lead -and iodide- deficient (d-HPs) by incorporating large organic cations, are characterized by a large hysteresis. The strategy of passivating defects by K, which has been successful in reducing the hysteresis of 3D perovskite perovskite solar cells, is inefficient with the d-HPs.

New Dication-Based Lead-Deficient 3D MAPbI and FAPbI "d-HPs" Perovskites with Enhanced Stability.

Toxicity induced by the presence of lead and the rather poor stability of halide perovskite semiconductors represent the major issues for their large-scale application. We previously reported a new family of lead- and iodide-deficient MAPbI and FAPbI perovskites called d-HPs (for lead- and iodide-deficient halide perovskites) based on two organic cations: hydroxyethylammonium HO-(CH)-NH (HEA) and thioethylammonium HS-(CH)-NH (TEA). In this article, we report the use of an organic dication, 2-hydroxypropane-1,3-diaminium (2-propanol 1,3 diammonium), named PDA, to create new 3D d-HPs based on the MAPbI and FAPbI network with general formulations of (PDA)(MA)[PbI] and (PDA)(FA)[PbI], respectively.

Exploring Solar Cells Based on Lead- and Iodide-Deficient Halide Perovskite (d-HP) Thin Films.

Perovskite solar cells have become more and more attractive and competitive. However, their toxicity induced by the presence of lead and their rather low stability hinders their potential and future commercialization. Reducing lead content while improving stability then appears as a major axis of development.