Methylammonium (MA) lead iodide perovskite (CH3NH3PbI3) plays an important role in light absorption and carrier transport in efficient organic-inorganic perovskite solar cells [1].  In my talk, the first theoretical estimation of effective masses of photocarriers and the role of MA cation in CH3NH3PbI3 will be discussed.DFT calculations have been performed with the generalized gradient approximation. From the charge density of the two-fold degenerate states ((a) and (b)) of CBM and those ((c) and (d)) of VBM, one can see that photogenerated electrons around CBM and holes around VBM exist separately, results related to the ambipolar transport nature of the material.  Effective masses of photogenerated electrons and holes are estimated to be me* =0.23m0 and mh* = 0.29m0, respectively, including spin-orbit coupling (SOC) effects. This result is consistent with the long-range ambipolar transport property and with the larger diffusion constant for electrons compared with that for holes in the perovskite, which enable efficient photovoltaic conversion [2].We also have focused our attention on the MA cation and studied the role it plays in the electronic/optical features of the perovskite, paying attention mainly to the iodide compound.References J. Bisquert, J. Phys. Chem. Lett, 4 , 2597 (2013).G. Giorgi, J. Fujisawa, H. Segawa, K. Yamashita, J. Phys. Chem. Lett, 4 , 4213 (2013).

Structural and electronic properties featuring ambipolar transport in methylammonium lead iodide perovskite: A DFT analysis

248th National Meeting (2014)

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