Mechanistic insights into the key role of methylammonium iodide in the stability of perovskite materials

The possible mechanisms damaging perovskite solar cells have attracted considerable attention in the photovoltaic community. This study answers specifically open problems regarding the critical role of methylammonium iodide (MAI) in investigations as well as stabilizing the perovskite cells. Surprisingly, we found that when the molar ratio between PbI2 : MAI precursor solution increased from 1 : 5 to 1 : 25, the stability of perovskite cells dramatically increased over time. The stability of perovskite in the air without any masking in the average stoichiometry was about five days, while when the amount of MAI precursor solution increased to 5, the perovskite film was unchanged for about 13 days; eventually, when the value of MAI precursor solution enhanced to 25, the perovskite film stayed intact for 20 days. The outstanding XRD results indicated that the intensity of perovskite's Miler indices increased significantly after 24 h, and the MAI's Miler indices decreased, which means that the amount of MAI was consumed to renew the perovskite crystal structure. In particular, the results suggested that the charging of MAI using the excess molar ratio of MAI reconstructs the perovskite material and stabilizes the crystal structure over time. Therefore, it is crucial that the main preparation procedure of perovskite material is optimized to 1 unit of Pb and 25 units of MAI in a two-step procedure in the literature.

[1]  Bingqiang Cao,et al.  Guanidinium cation passivated Pb-Cu alloyed perovskite for efficient low-toxicity solar cells , 2021 .

[2]  Hui-ping Wu,et al.  Slow Passivation and Inverted Hysteresis for Hybrid Tin Perovskite Solar Cells Attaining 13.5% via Sequential Deposition. , 2021, The journal of physical chemistry letters.

[3]  W. Chae,et al.  Synergistic passivation of MAPbI3 perovskite solar cells by compositional engineering using acetamidinium bromide additives , 2021 .

[4]  J. Xie,et al.  Modulating MAPbI3 perovskite solar cells by amide molecules: Crystallographic regulation and surface passivation , 2021 .

[5]  L. Duchêne,et al.  Vapor Transport Deposition of Methylammonium Iodide for Perovskite Solar Cells , 2021 .

[6]  Jay B. Patel,et al.  Limits to Electrical Mobility in Lead-Halide Perovskite Semiconductors , 2021, The journal of physical chemistry letters.

[7]  R. Friend,et al.  Efficient light-emitting diodes from mixed-dimensional perovskites on a fluoride interface , 2020, Nature Electronics.

[8]  Y. Xiang,et al.  Coordination modulated crystallization and defect passivation in high quality perovskite film for efficient solar cells , 2020 .

[9]  J. Jung,et al.  Methylammonium Iodide-Mediated Controlled Crystal Growth of CsPbI2Br Film for Efficient and Stable All-Inorganic Perovskite Solar Cells. , 2020, ACS applied materials & interfaces.

[10]  Babak Pashaei,et al.  Molecularly Engineered Near‐Infrared Light‐Emitting Electrochemical Cells , 2020, Advanced Functional Materials.

[11]  M. Thelakkat,et al.  Role of PCBM in the Suppression of Hysteresis in Perovskite Solar Cells , 2020, Advanced Functional Materials.

[12]  Xinran S. Wang,et al.  In Situ Defect Passivation with Silica Oligomer for Enhanced Performance and Stability of Perovskite Solar Cells , 2019, Advanced Materials Interfaces.

[13]  Yue Hu,et al.  A Review on Additives for Halide Perovskite Solar Cells , 2019, Advanced Energy Materials.

[14]  K. Zhu,et al.  Additive Engineering for Efficient and Stable Perovskite Solar Cells , 2019, Advanced Energy Materials.

[15]  Tingshuai Li,et al.  Off-Stoichiometric Methylammonium Iodide Passivated Large Grain Perovskite Film in Ambient Air for Efficient Inverted Solar Cells. , 2019, ACS applied materials & interfaces.

[16]  T. Miyadera,et al.  Tuning methylammonium iodide amount in organolead halide perovskite materials by post-treatment for high-efficiency solar cells. , 2019, ACS applied materials & interfaces.

[17]  Dong Suk Kim,et al.  Methylammonium Chloride Induces Intermediate Phase Stabilization for Efficient Perovskite Solar Cells , 2019, Joule.

[18]  V. Bulović,et al.  Controllable Perovskite Crystallization via Antisolvent Technique Using Chloride Additives for Highly Efficient Planar Perovskite Solar Cells , 2019, Advanced Energy Materials.

[19]  Jinsong Huang,et al.  Bilateral alkylamine for suppressing charge recombination and improving stability in blade-coated perovskite solar cells , 2019, Science Advances.

[20]  T. Miyasaka,et al.  Halide Perovskite Photovoltaics: Background, Status, and Future Prospects. , 2019, Chemical reviews.

[21]  Bao Zhang,et al.  High‐Performance Perovskite Solar Cells with Enhanced Environmental Stability Based on a (p‐FC6H4C2H4NH3)2[PbI4] Capping Layer , 2019, Advanced Energy Materials.

[22]  A. Jen,et al.  Two-Dimensional Perovskite Solar Cells with 14.1% Power Conversion Efficiency and 0.68% External Radiative Efficiency , 2018, ACS Energy Letters.

[23]  Hongwei Song,et al.  Enhanced Performance of Perovskite Solar Cells with Zinc Chloride Additives. , 2017, ACS applied materials & interfaces.

[24]  Yanfa Yan,et al.  Synergistic Effects of Lead Thiocyanate Additive and Solvent Annealing on the Performance of Wide-Bandgap Perovskite Solar Cells , 2017 .

[25]  C. Brabec,et al.  Deciphering the Role of Impurities in Methylammonium Iodide and Their Impact on the Performance of Perovskite Solar Cells , 2016 .

[26]  A. Jen,et al.  Effects of formamidinium and bromide ion substitution in methylammonium lead triiodide toward high-performance perovskite solar cells , 2016 .

[27]  S. Meloni,et al.  Ionic polarization-induced current–voltage hysteresis in CH3NH3PbX3 perovskite solar cells , 2016, Nature Communications.

[28]  Laura M. Herz,et al.  Temperature‐Dependent Charge‐Carrier Dynamics in CH3NH3PbI3 Perovskite Thin Films , 2015 .

[29]  M. Grätzel,et al.  Sequential deposition as a route to high-performance perovskite-sensitized solar cells , 2013, Nature.

[30]  David B. Mitzi,et al.  Design, Structure, and Optical Properties of Organic-Inorganic Perovskites Containing an Oligothiophene Chromophore. , 1999, Inorganic chemistry.

[31]  He Tian,et al.  Improved Efficiency and Stability of Perovskite Solar Cells Induced by CO Functionalized Hydrophobic Ammonium‐Based Additives , 2018, Advanced materials.