Fig. 6: Fate of photogenerated carriers.
From: Tracking carrier and exciton dynamics in mixed-cation lead mixed-halide perovskite thin films
Two possible paths of carriers to a recombine with holes in the valence band, involving (or without involving) a third carrier, and b bind with holes, forming excitons in the excitonic levels. CB and VB mean conduction band and valence band, respectively. c The time evolution of f2 at different pump fluences. d The f2 evolution for 83 μJ/cm2. The inset illustrates three stages of relaxation between the free carrier band (continuum) and the exciton level (1s level) (denoted by black arrows). The red ''X” denotes the transition has been forbidden because of excitonic state-filling effect. The orange and blue arrows denote the carrier recombination and exciton decay, respectively. Errors of f2 are standard error that is determined by calculating the 95% confidence interval, based on residual values and Jacobian matrix obtained from the fits to Eq. (7).
