We report on accelerated degradation
testing of MAPbX<sub>3</sub> films (X = I or Br) by exposure to concentrated
sunlight of 100
suns and show that the evolution of light absorption and the corresponding
structural modifications are dependent on the type of halide ion and
the exposure temperature. One hour of such exposure provides a photon
dose equivalent to that of one sun exposure for 100 hours. The degradation
in absorption of MAPbI<sub>3</sub> films after exposure to 100 suns
for 60 min at elevated sample temperature (∼45–55 °C),
due to decomposition of the hybrid perovskite material, is documented.
No degradation was observed after exposure to the same sunlight concentration
but at a lower sample temperature (∼25 °C). No photobleaching
or decomposition of MAPbBr<sub>3</sub> films was observed after exposure
to similar stress conditions (light intensity, dose, and temperatures).
Our results indicate that the degradation is highly dependent on the
hybrid perovskite composition and can be light- and thermally enhanced