Substance and shadow of formamidinium lead triiodide based solar cells

The current decade has witnessed a surge of progress in the investigation of methyl ammonium lead iodide (MAPbI(3)) perovskites for solar cell fabrication due to their intriguing electro-optical properties, despite the intrinsic degradation of the material that has restricted its commercialisation. As a promising alternative, solar cells based on its formamidinium analogue, FAPbI(3), are currently being actively pursued for having demonstrated a certified efficiency of 24.4%, while the room-temperature conversion to a non-perovskite delta-phase impedes its further commercialisation, and strategies have been adopted to overcome this phase instability. An in-depth and real-time understanding of microstructural relationships with optoelectronic properties and their underlying mechanisms using operando in situ spectroscopic techniques is paramount. Thus, the design and development of a new process, data driven methodology, characterization and evaluation protocols for perovskite absorber layers and the fabricated devices is a judicious research direction. Here, in this perspective, we shed light on the compositional, surface engineering and crystallization kinetics manipulations for FAPbI(3), followed by a proposition for unified testing protocols, for scalling of devices from the lab to the market.

Automated summary

The research progress on MAPbI(3) perovskites has been significant, but FAPbI(3) faces challenges due to phase instability. Strategies are being developed to overcome these challenges by manipulating crystallization kinetics and surface engineering.