Exploring the Effects of the Pb²⁺ Substitution in MAPbI₃ on the Photovoltaic Performance of the Hybrid Perovskite Solar Cells

Here we report a systematic study of the Pb²⁺ substitution in the hybrid iodoplumbate MAPbI₃ with a series of elements affecting optoelectronic, structural, and morphological properties of the system. It has been shown that even partial replacement of lead with Cd²⁺, Zn²⁺, Fe²⁺, Ni²⁺, Co²⁺, In³⁺, Bi³⁺, Sn⁴⁺, and Ti⁴⁺ results in a significant deterioration of the photovoltaic characteristics. On the contrary, Hg-containing hybrid MAPb_1–<i>x</i>Hg_<i>x</i>I₃ salts demonstrated a considerably improved solar cell performance at optimal mercury loading. This result opens up additional dimension in the compositional engineering of the complex lead halides for designing novel photoactive materials with advanced optoelectronic and photovoltaic properties

Highly Efficient All-Inorganic Planar Heterojunction Perovskite Solar Cells Produced by Thermal Coevaporation of CsI and PbI₂

We report here all inorganic CsPbI₃ planar junction perovskite solar cells fabricated by thermal coevaporation of CsI and PbI₂ precursors. The best devices delivered power conversion efficiency (PCE) of 9.3 to 10.5%, thus coming close to the reference MAPbI₃-based devices (PCE ≈ 12%). These results emphasize that all inorganic lead halide perovskites can successfully compete in terms of photovoltaic performance with the most widely used hybrid materials such as MAPbI₃

Probing the Intrinsic Thermal and Photochemical Stability of Hybrid and Inorganic Lead Halide Perovskites

We report a careful and systematic study of thermal and photochemical degradation of a series of complex haloplumbates APbX₃ (X = I, Br) with hybrid organic (A⁺ = CH₃NH₃) and inorganic (A⁺ = Cs⁺) cations under anoxic conditions (i.e., without exposure to oxygen and moisture by testing in an inert glovebox environment). We show that the most common hybrid materials (e.g., MAPbI₃) are intrinsically unstable with respect to the heat- and light-induced stress and, therefore, can hardly sustain the real solar cell operation conditions. On the contrary, the cesium-based all-inorganic complex lead halides revealed far superior stability and, therefore, provide an impetus for creation of highly efficient and stable perovskite solar cells that can potentially achieve pragmatic operational benchmarks