10.1021/jacs.5b08770.s001 Carlito S. Ponseca Carlito S. Ponseca Eline M. Hutter Eline M. Hutter Piotr Piatkowski Piotr Piatkowski Boiko Cohen Boiko Cohen Torbjörn Pascher Torbjörn Pascher Abderrazzak Douhal Abderrazzak Douhal Arkady Yartsev Arkady Yartsev Villy Sundström Villy Sundström Tom J. Savenije Tom J. Savenije Mechanism of Charge Transfer and Recombination Dynamics in Organo Metal Halide Perovskites and Organic Electrodes, PCBM, and Spiro-OMeTAD: Role of Dark Carriers American Chemical Society 2015 MAPbI 3. decay electron electrode PCBM subpicosecond time scale interface doping injection charge transfer dynamics concentration perovskite Organo Metal Halide Perovskites recombination 2015-12-30 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Mechanism_of_Charge_Transfer_and_Recombination_Dynamics_in_Organo_Metal_Halide_Perovskites_and_Organic_Electrodes_PCBM_and_Spiro_OMeTAD_Role_of_Dark_Carriers/2093875 Despite the unprecedented interest in organic–inorganic metal halide perovskite solar cells, quantitative information on the charge transfer dynamics into selective electrodes is still lacking. In this paper, we report the time scales and mechanisms of electron and hole injection and recombination dynamics at organic PCBM and Spiro-OMeTAD electrode interfaces. On the one hand, hole transfer is complete on the subpicosecond time scale in MAPbI<sub>3</sub>/Spiro-OMeTAD, and its recombination rate is similar to that in neat MAPbI<sub>3</sub>. This was found to be due to a high concentration of dark charges, i.e., holes brought about by unintentional p-type doping of MAPbI<sub>3</sub>. Hence, the total concentration of holes in the perovskite is hardly affected by optical excitation, which manifested as similar decay kinetics. On the other hand, the decay of the photoinduced conductivity in MAPbI<sub>3</sub>/PCBM is on the time scale of hundreds of picoseconds to several nanoseconds, due to electron injection into PCBM and electron–hole recombination at the interface occurring at similar rates. These results highlight the importance of understanding the role of dark carriers in deconvoluting the complex photophysical processes in these materials. Moreover, optimizing the preparation processes wherein undesired doping is minimized could prompt the use of organic molecules as a more viable electrode substitute for perovskite solar cell devices.