Controllable Grain Morphology of Perovskite Absorber Film by Molecular Self-Assembly toward Efficient Solar Cell Exceeding 17%.

The highly developed crystallization process with respect to perovskite thin films is favorable for efficient solar cells. Here, an innovative intermolecular self-assembly approach was employed to retard the crystallization of PbI2 in dimethylformamide (DMF) by additional solvent of dimethyl sulfoxide (DMSO), which was proved to be capable of coordinating with PbI2 by coordinate covalent bond. The obtained PbI2(DMSO)x (0 ≤ x ≤ 1.86) complexes tend to be closely packed by means of intermolecular self-assembly. Afterward, an intramolecular exchange of DMSO with CH3NH3I (MAI) enabled the complexes to deform their shape and finally to reorganize to be an ultraflat and dense thin film of CH3NH3PbI3. The controllable grain morphology of perovskite thin film allows obtaining a power conversion efficiency (PCE) above 17% and a stabilized power output above 16% within 240 s by controlling DMSO species in the complex-precursor system (CPS). The present study gives a reproductive and facile strategy toward high quality of perovskite thin films and efficient solar cells.

[1]  Shuzi Hayase,et al.  Reproducible Fabrication of Efficient Perovskite-based Solar Cells: X-ray Crystallographic Studies on the Formation of CH3NH3PbI3 Layers , 2014 .

[2]  M. Grätzel,et al.  A hole-conductor–free, fully printable mesoscopic perovskite solar cell with high stability , 2014, Science.

[3]  M. Grätzel,et al.  Title: Long-Range Balanced Electron and Hole Transport Lengths in Organic-Inorganic CH3NH3PbI3 , 2017 .

[4]  Xing Zhang,et al.  Hysteretic Behavior upon Light Soaking in Perovskite Solar Cells Prepared via Modified Vapor-Assisted Solution Process. , 2015, ACS applied materials & interfaces.

[5]  Young Chan Kim,et al.  Compositional engineering of perovskite materials for high-performance solar cells , 2015, Nature.

[6]  Sung Cheol Yoon,et al.  Benefits of very thin PCBM and LiF layers for solution-processed p–i–n perovskite solar cells , 2014 .

[7]  Qi Chen,et al.  Planar heterojunction perovskite solar cells via vapor-assisted solution process. , 2014, Journal of the American Chemical Society.

[8]  Peng Gao,et al.  Mesoscopic CH3NH3PbI3/TiO2 heterojunction solar cells. , 2012, Journal of the American Chemical Society.

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

[10]  Qi Chen,et al.  Low-temperature solution-processed perovskite solar cells with high efficiency and flexibility. , 2014, ACS nano.

[11]  Henry J. Snaith,et al.  Efficient planar heterojunction perovskite solar cells by vapour deposition , 2013, Nature.

[12]  J. Teuscher,et al.  Efficient Hybrid Solar Cells Based on Meso-Superstructured Organometal Halide Perovskites , 2012, Science.

[13]  M. Winnik.  Latex film formation , 1997 .

[14]  Tsutomu Miyasaka,et al.  Organometal halide perovskites as visible-light sensitizers for photovoltaic cells. , 2009, Journal of the American Chemical Society.

[15]  Kun Zhang,et al.  Retarding the crystallization of PbI2 for highly reproducible planar-structured perovskite solar cells via sequential deposition , 2014 .

[16]  Henry J Snaith,et al.  Efficient organometal trihalide perovskite planar-heterojunction solar cells on flexible polymer substrates , 2013, Nature Communications.

[17]  Fan Zuo,et al.  Additive Enhanced Crystallization of Solution‐Processed Perovskite for Highly Efficient Planar‐Heterojunction Solar Cells , 2014, Advanced materials.

[18]  Yixin Zhao,et al.  Controllable Sequential Deposition of Planar CH₃NH₃PbI₃ Perovskite Films via Adjustable Volume Expansion. , 2015, Nano letters.

[19]  B. Jia,et al.  Perovskite-based low-cost and high-efficiency hybrid halide solar cells , 2014 .

[20]  Yan Yao,et al.  Solvent engineering towards controlled grain growth in perovskite planar heterojunction solar cells. , 2015, Nanoscale.

[21]  J. Selbin,et al.  Metallic complexes of dimethylsulphoxide , 1961 .

[22]  M. Green,et al.  The emergence of perovskite solar cells , 2014, Nature Photonics.

[23]  H. Miyamae,et al.  THE CRYSTAL STRUCTURE OF LEAD(II) IODIDE-DIMETHYLSULPHOXIDE(1/2), PbI2(dmso)2 , 1980 .

[24]  Qi Chen,et al.  Controllable self-induced passivation of hybrid lead iodide perovskites toward high performance solar cells. , 2014, Nano letters.

[25]  M. White,et al.  Alkylammonium lead halides. Part 2. CH3NH3PbX3 (X = Cl, Br, I) perovskites: cuboctahedral halide cages with isotropic cation reorientation , 1990 .

[26]  Laura M Herz,et al.  High Charge Carrier Mobilities and Lifetimes in Organolead Trihalide Perovskites , 2013, Advanced materials.

[27]  Kangning Liang,et al.  Synthesis and Characterization of Organic−Inorganic Perovskite Thin Films Prepared Using a Versatile Two-Step Dipping Technique , 1998 .

[28]  Guangda Niu,et al.  Multifunctional perovskite capping layers in hybrid solar cells , 2014 .

[29]  N. Park,et al.  Lead Iodide Perovskite Sensitized All-Solid-State Submicron Thin Film Mesoscopic Solar Cell with Efficiency Exceeding 9% , 2012, Scientific Reports.

[30]  Yong Qiu,et al.  Montmorillonite as bifunctional buffer layer material for hybrid perovskite solar cells with protection from corrosion and retarding recombination , 2014 .

[31]  S. Ito,et al.  Lead-Halide Perovskite Solar Cells by CH3NH3I Dripping on PbI2-CH3NH3I-DMSO Precursor Layer for Planar and Porous Structures Using CuSCN Hole-Transporting Material. , 2015, The journal of physical chemistry letters.

[32]  Laura M. Herz,et al.  Electron-Hole Diffusion Lengths Exceeding 1 Micrometer in an Organometal Trihalide Perovskite Absorber , 2013, Science.

[33]  Yang Yang,et al.  Interface engineering of highly efficient perovskite solar cells , 2014, Science.

[34]  Sang Il Seok,et al.  High-performance photovoltaic perovskite layers fabricated through intramolecular exchange , 2015, Science.

[35]  S. Hsiao,et al.  Efficient and Uniform Planar‐Type Perovskite Solar Cells by Simple Sequential Vacuum Deposition , 2014, Advanced materials.