On the Role of Interfaces in Planar-Structured HC(NH2 )2 PbI3 Perovskite Solar Cells.

Planar-structured HC(NH2 )2 PbI3 (FAPbI3 ) perovskite solar cells were prepared via a two-step deposition process. To investigate the role of interface, the perovskite morphology was intentionally modified by varying HC(NH2 )2 I concentration. Surface and grain sizes of the deposited FAPbI3 became rougher and larger as the HC(NH2 )2 I concentration decreased from 58.2 to 40.7 mM. Average photocurrent was improved but photovoltage deteriorated slightly with decreasing concentration. Consequently, the average efficiency was improved from 7.82 % to 10.70 % and the best efficiency of 12.17 % was obtained at 40.7 mM. Photoluminescence (PL) at TiO2 /FAPbI3 interface was reduced with decreasing concentration, which was, however, reversed at FAPbI3 /spiro-MeOTAD one. By correlating PL data and the photovoltaic performance, we concluded that the TiO2 /perovskite interface plays a crucial role in determining photocurrent while the perovskite/spiro-MeOTAD interface is important in governing photovoltage.

[1]  M. Johnston,et al.  Formamidinium lead trihalide: a broadly tunable perovskite for efficient planar heterojunction solar cells , 2014 .

[2]  Nam-Gyu Park,et al.  Growth of CH3NH3PbI3 cuboids with controlled size for high-efficiency perovskite solar cells. , 2014, Nature nanotechnology.

[3]  Mercouri G Kanatzidis,et al.  Semiconducting tin and lead iodide perovskites with organic cations: phase transitions, high mobilities, and near-infrared photoluminescent properties. , 2013, Inorganic chemistry.

[4]  H. H. Tippins.  Optical Absorption and Photoconductivity in the Band Edge of β − Ga 2 O 3 , 1965 .

[5]  Peng Gao,et al.  Mixed-organic-cation perovskite photovoltaics for enhanced solar-light harvesting. , 2014, Angewandte Chemie.

[6]  H. Takakura,et al.  Sputtered ZnO-based buffer layer for band offset control in Cu(In,Ga)Se2 solar cells , 2011 .

[7]  S. Ito,et al.  Double functions of porous TiO2 electrodes on CH3NH3PbI3 perovskite solar cells: Enhancement of perovskite crystal transformation and prohibition of short circuiting , 2014 .

[8]  Martin Schreyer,et al.  Synthesis and crystal chemistry of the hybrid perovskite (CH3NH3) PbI3 for solid-state sensitised solar cell applications , 2013 .

[9]  V. Goldschmidt.  Krystallbau und chemische Zusammensetzung , 1927 .

[10]  N. Davidson,et al.  Mutations in M2 alter the selectivity of the mouse nicotinic acetylcholine receptor for organic and alkali metal cations , 1992, The Journal of general physiology.

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

[12]  Nam-Gyu Park,et al.  Morphology-photovoltaic property correlation in perovskite solar cells: One-step versus two-step deposition of CH3NH3PbI3 , 2014 .

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

[14]  Nam-Gyu Park,et al.  11% Efficient Perovskite Solar Cell Based on ZnO Nanorods: An Effective Charge Collection System , 2014 .

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

[16]  Juan Bisquert,et al.  Slow Dynamic Processes in Lead Halide Perovskite Solar Cells. Characteristic Times and Hysteresis. , 2014, The journal of physical chemistry letters.

[17]  Nam-Gyu Park,et al.  Organolead Halide Perovskite: New Horizons in Solar Cell Research , 2014 .

[18]  Nam-Gyu Park,et al.  High‐Efficiency Perovskite Solar Cells Based on the Black Polymorph of HC(NH2)2PbI3 , 2014, Advanced materials.

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

[20]  W. T. Welford,et al.  Optical estimation of statistics of surface roughness from light scattering measurements , 1977 .

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

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

[23]  Nam-Gyu Park,et al.  6.5% efficient perovskite quantum-dot-sensitized solar cell. , 2011, Nanoscale.

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