High-Performance CH3NH3PbI3-Inverted Planar Perovskite Solar Cells with Fill Factor Over 83% via Excess Organic/Inorganic Halide.
The reduction of charge carrier recombination and intrinsic defect density in organic-inorganic halide perovskite absorber materials is a prerequisite to achieving high-performance perovskite solar cells with good efficiency and stability. Here, we fabricated inverted planar perovskite solar cells by incorporation of a small amount of excess organic/inorganic halide (methylammonium iodide (CH3NH3I; MAI), formamidinium iodide (CH(NH2)2I; FAI), and cesium iodide (CsI)) in CH3NH3PbI3 perovskite film. Larger crystalline grains and enhanced crystallinity in CH3NH3PbI3 perovskite films with excess organic/inorganic halide reduce the charge carrier recombination and defect density, leading to enhanced device efficiency (MAI+: 14.49 ± 0.30%, FAI+: 16.22 ± 0.38% and CsI+: 17.52 ± 0.56%) compared to the efficiency of a control MAPbI3 device (MAI: 12.63 ± 0.64%) and device stability. Especially, the incorporation of a small amount of excess CsI in MAPbI3 perovskite film leads to a highly reproducible fill factor of over 83%, increased open-circuit voltage (from 0.946 to 1.042 V), and short-circuit current density (from 18.43 to 20.89 mA/cm2).
['Jahandar|Muhammad|M|http://orcid.org/0000-0002-2058-263X', 'Khan|Nasir|N|http://orcid.org/0000-0003-3119-8702', 'Lee|Hang Ken|HK|http://orcid.org/0000-0002-2104-5334', 'Lee|Sang Kyu|SK|http://orcid.org/0000-0002-7568-2902', 'Shin|Won Suk|WS|http://orcid.org/0000-0001-7151-519X', 'Lee|Jong-Cheol|JC|http://orcid.org/0000-0002-2892-2213', 'Song|Chang Eun|CE|http://orcid.org/0000-0001-6910-8755', 'Moon|Sang-Jin|SJ|http://orcid.org/0000-0002-0451-8558']
perovskite solar cells organic/inorganic halides defect density CH3NH3PbI3 grain growth