Microseconds, milliseconds and seconds: deconvoluting the dynamic   behaviour of planar perovskite solar cells
  Perovskite solar cells (PSC) are shown to behave as coupled ionic-electronic conductors with strong evidence that the ionic environment moderates both the rate of electron-hole recombination and the band offsets in planar PSC. Numerous models have been presented to explain the behavior of perovskite solar cells, but to date no single model has emerged that can explain both the frequency and time dependent response of the devices. Here we present a straightforward coupled ionic-electronic model that can be used to explain the large amplitude transient behavior and the impedance response of PSC. 
Adam Pockett, Giles Eperon, Nobuya Sakai, Henry Snaith, Laurence M   Peter and Petra J Cameron
cond-mat.mtrl-sci physics.chem-ph