10.1021/acs.jpclett.6b01958.s001 Jun Dai Jun Dai Yongping Fu Yongping Fu Lydia H. Manger Lydia H. Manger Morgan T. Rea Morgan T. Rea Leekyoung Hwang Leekyoung Hwang Randall H. Goldsmith Randall H. Goldsmith Song Jin Song Jin Carrier Decay Properties of Mixed Cation Formamidinium–Methylammonium Lead Iodide Perovskite [HC(NH<sub>2</sub>)<sub>2</sub>]<sub>1–<i>x</i></sub>[CH<sub>3</sub>NH<sub>3</sub>]<sub><i>x</i></sub>PbI<sub>3</sub> Nanorods American Chemical Society 2016 iodide perovskites x PbI 3 HC FA 0.4 MA 0.6 PbI 3 displays PL CH 3 NH 3 carrier Decay Properties MAPbI 3 nanorods cation report carrier decay dynamics 2016-11-23 00:00:00 Journal contribution https://acs.figshare.com/articles/journal_contribution/Carrier_Decay_Properties_of_Mixed_Cation_Formamidinium_Methylammonium_Lead_Iodide_Perovskite_HC_NH_sub_2_sub_sub_2_sub_sub_1_i_x_i_sub_CH_sub_3_sub_NH_sub_3_sub_sub_i_x_i_sub_PbI_sub_3_sub_Nanorods/4264472 Organic–inorganic lead iodide perovskites are efficient materials for photovoltaics and light-emitting diodes. We report carrier decay dynamics of nanorods of mixed cation formamidinium and methylammonium lead iodide perovskites [HC­(NH<sub>2</sub>)<sub>2</sub>]<sub>1–<i>x</i></sub>[CH<sub>3</sub>NH<sub>3</sub>]<sub><i>x</i></sub>PbI<sub>3</sub> (FA<sub>1–<i>x</i></sub>MA<sub><i>x</i></sub>PbI<sub>3</sub>) synthesized through a simple solution method. The structure and FA/MA composition ratio of the single-crystal FA<sub>1–<i>x</i></sub>MA<sub><i>x</i></sub>PbI<sub>3</sub> nanorods are fully characterized, which shows that the mixed cation FA<sub>1–<i>x</i></sub>MA<sub><i>x</i></sub>PbI<sub>3</sub> nanorods are stabilized in the perovskite structure. The photoluminescence (PL) emission from FA<sub>1–<i>x</i></sub>MA<sub><i>x</i></sub>PbI<sub>3</sub> nanorods continuously shifts from 821 to 782 nm as the MA ratio (<i>x</i>) increases from 0 to 1 and is shown to be inhomogeneously broadened. Time-resolved PL from individual FA<sub>1–<i>x</i></sub>MA<sub><i>x</i></sub>PbI<sub>3</sub> nanorods demonstrates that lifetimes of mixed cation FA<sub>1–<i>x</i></sub>MA<sub><i>x</i></sub>PbI<sub>3</sub> nanorods are longer than those of the pure FAPbI<sub>3</sub> or MAPbI<sub>3</sub> nanorods, and the FA<sub>0.4</sub>MA<sub>0.6</sub>PbI<sub>3</sub> displays the longest average PL lifetime of about 2 μs. These results suggest that mixed cation FA<sub>1–<i>x</i></sub>MA<sub><i>x</i></sub>PbI<sub>3</sub> perovskites are promising for high-efficiency photovoltaics and other optoelectronic applications.