Bigger and smooth surface crystal growth of MAPbI3 using EACl and DMSO

Graduate school of LSSE, Kyushu institute of technology, Kitakyushu, Japan

M. Vigneshwaran*, T. Nishimura, Y. Ogomi, S.S. Pandey, Tayo Toyoda, Shen Qing,

S. Hayase*

E-mail: murugan-vigneshwaran@edu.life.kyutech.ac.jp, hayase@life.kyutech.ac.jp

Perovskite based solar cells studies are highly important due

to its rapid increase in efficiency up to 20.1%. Therefore more attention is needed for

realizing the highly efficient perovskite solar cell. Although the efficiency of the solar cells

depends on the various parameters like perovskite materials, thickness, HTL materials and so

on, highly efficient perovskite solar cells basically requires controlled crystal growth with

smooth surface and more surface area coverage. We already reported that EACl was the

suitable chloride precursor for the crystal growth of MAPbI3 in one step method[1][2]

. Here we

report the improvement in CH3NH3PbI3 crystals with smooth surface by adding EACl as the

additive and DMSO as the solvent in two step method.

In CH3NH3PbI3 perovskite addition of Cl- ions is very crucial

since it decides the crystal size of the perovskite. But bigger perovskite crystals are not

sufficient in order to achieve the good performance for the solar cells. Bigger crystals with

smoother surface are highly required in order to get the good efficiency since it reduces the

interface losses between the perovskite and HTL layer. We found that after using DMSO as

the solvent and EACl as the additive results in the better crystallization of MAPbI3 with

smoother surface which is very crucial in the field of perovskite solar cells.

References

[1] Murugan, Vigneshwaran, and Hayase, Shuzi. " Controlled crystal growth of lead halide perovskites

by adding different types of chloride precursor." Chemistry of Materials (Under Review).

[2] " Controlled crystal growth of lead halide perovskites by adding different types of chloride

precursor."（JSAP 62nd spring Meeting, 2015）