Intrinsic Thermal Instability of Methylammonium Lead Trihalide Perovskite

TLDR

Organolead halide perovskites are emerging as high‑efficiency (>20 %) light absorbers for hybrid solar cells, fabricated at low temperatures (<100 °C) via inexpensive solution routes, yet their long‑term stability remains a critical barrier to industrial deployment. The study shows that methylammonium lead triiodide perovskite decomposes significantly at 85 °C even under inert conditions, violating international standards and highlighting its low formation energy as a major bottleneck, thereby motivating the search for thermally more robust perovskite families.

Abstract

Organolead halide perovskites currently are the new front-runners as light absorbers in hybrid solar cells, as they combine efficiencies passing already 20% with deposition temperatures below 100 °C and cheap solution-based fabrication routes. Long-term stability remains a major obstacle for application on an industrial scale. Here, it is demonstrated that significant decomposition effects already occur during annealing of a methylammonium lead triiode perovskite at 85 °C even in inert atmosphere thus violating international standards. The observed behavior supports the view of currently used perovskite materials as soft matter systems with low formation energies, thus representing a major bottleneck for their application, especially in countries with high average temperatures. This result can trigger a broader search for new perovskite families with improved thermal stability.