Fabrication-Method-Dependent Excited State Dynamics in CH₃NH₃PbI₃ Perovskite Films.

ABSTRACT: Understanding the excited-state dynamics in perovskite photovoltaics is necessary for progress in these materials, but changes in dynamics depending on the fabrication processes used for perovskite photoactive layers remain poorly characterised. Here we report a comparative study on femtosecond transient absorption (TA) in CH₃NH₃PbI₃ perovskite films fabricated by various solution-processing methods. The grain sizes and the number of voids between grains on each film varied according to the film synthesis method. At the low excitation fluence of 0.37 μJ cm^-2, fast signal drops in TA dyanmics within 1.5 ps were observed in all perovskite films, but the signal drop magnitudes differed becuase of the variations in charge migration to trap states and

SUBMITTER: Kim IS 

PROVIDER: S-EPMC5705678 | biostudies-literature | 2017 Nov

REPOSITORIES: biostudies-literature