Copper Salts Doped Spiro‐OMeTAD for High‐Performance Perovskite Solar Cells

The development of effective and stable hole transporting materials (HTMs) is very important for achieving high-performance planar perovskite solar cells (PSCs). Herein, copper salts (cuprous thiocyanate (CuSCN) or cuprous iodide (CuI)) doped 2,2,7,7-tetrakis(N,N-di-p-methoxyphenylamine)-9,9-spirobifluorene (spiro-OMeTAD) based on a solution processing as the HTM in PSCs is demonstrated. The incorporation of CuSCN (or CuI) realizes a p-type doping with efficient charge transfer complex, which results in improved film conductivity and hole mobility in spiro-OMeTAD:CuSCN (or CuI) composite films. As a result, the PCE is largely improved from 14.82% to 18.02% due to obvious enhancements in the cell parameters of short-circuit current density and fill factor. Besides the HTM role, the composite film can suppress the film aggregation and crystallization of spiro-OMeTAD films with reduced pinholes and voids, which slows down the perovskite decomposition by avoiding the moisture infiltration to some extent. The finding in this work provides a simple method to improve the efficiency and stability of planar perovskite solar cells.

[1]  L. Liao,et al.  Dual roles of MoO3-doped pentacene thin films as hole-extraction and multicharge-separation functions in pentacene/C60 heterojunction organic solar cells , 2013 .

[2]  Samson A. Jenekhe,et al.  Solution‐Processed, Alkali Metal‐Salt‐Doped, Electron‐Transport Layers for High‐Performance Phosphorescent Organic Light‐Emitting Diodes , 2012 .

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

[4]  P. Chou,et al.  Application of F4TCNQ doped spiro-MeOTAD in high performance solid state dye sensitized solar cells. , 2012, Physical chemistry chemical physics : PCCP.

[5]  L. Liao,et al.  Conductive Inorganic–Organic Hybrid Distributed Bragg Reflectors , 2015, Advanced materials.

[6]  E. Barea,et al.  New iridium complex as additive to the spiro-OMeTAD in perovskite solar cells with enhanced stability , 2014 .

[7]  Yun-Chorng Chang,et al.  Nickel Oxide Electrode Interlayer in CH3NH3PbI3 Perovskite/PCBM Planar‐Heterojunction Hybrid Solar Cells , 2014, Advanced materials.

[8]  Yang Yang,et al.  Moisture assisted perovskite film growth for high performance solar cells , 2014 .

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

[10]  Josef Salbeck,et al.  Solid-state dye-sensitized mesoporous TiO2 solar cells with high photon-to-electron conversion efficiencies , 1998, Nature.

[11]  Sang Il Seok,et al.  Solvent engineering for high-performance inorganic-organic hybrid perovskite solar cells. , 2014, Nature materials.

[12]  Peng Wang,et al.  An organic D-π-A dye for record efficiency solid-state sensitized heterojunction solar cells. , 2011, Nano letters.

[13]  A. Kahn,et al.  P-type doping of organic wide band gap materials by transition metal oxides: A case-study on Molybdenum trioxide , 2009 .

[14]  Xingyu Gao,et al.  Structure, Optical Absorption, and Performance of Organic Solar Cells Improved by Gold Nanoparticles in Buffer Layers. , 2015, ACS applied materials & interfaces.

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

[16]  Jeffrey A. Christians,et al.  An inorganic hole conductor for organo-lead halide perovskite solar cells. Improved hole conductivity with copper iodide. , 2014, Journal of the American Chemical Society.

[17]  Dongmei Li,et al.  Interfaces in perovskite solar cells. , 2015, Small.

[18]  L. Liao,et al.  Comparative studies on the inorganic and organic p-type dopants in organic light-emitting diodes with enhanced hole injection , 2013 .

[19]  Young Chan Kim,et al.  o-Methoxy substituents in spiro-OMeTAD for efficient inorganic-organic hybrid perovskite solar cells. , 2014, Journal of the American Chemical Society.

[20]  Xinhua Li,et al.  Origin of the high performance of perovskite solar cells with large grains , 2016 .

[21]  Sung‐Ho Jin,et al.  Highly Efficient Organic Hole Transporting Materials for Perovskite and Organic Solar Cells with Long‐Term Stability , 2016, Advanced materials.

[22]  Zhaokui Wang,et al.  Charge transport characteristics in P3HT:PCBM organic blends under illumination: Influence of metal work functions , 2012 .

[23]  Jang‐Joo Kim,et al.  High performance top-emitting organic light-emitting diodes with copper iodide-doped hole injection layer , 2008 .

[24]  Henk J. Bolink,et al.  Perovskite solar cells employing organic charge-transport layers , 2013, Nature Photonics.

[25]  Meng Li,et al.  Controllable Perovskite Crystallization by Water Additive for High‐Performance Solar Cells , 2015 .

[26]  Guangda Niu,et al.  Review of recent progress in chemical stability of perovskite solar cells , 2015 .

[27]  Oscar Miguel,et al.  Organo-metal halide perovskite-based solar cells with CuSCN as the inorganic hole selective contact , 2014 .

[28]  L. Liao,et al.  Inverted planar NH2CH=NH2PbI3 perovskite solar cells with 13.56% efficiency via low temperature processing. , 2015, Physical chemistry chemical physics : PCCP.

[29]  J. Kido,et al.  Origin of Enhanced Hole Injection in Inverted Organic Devices with Electron Accepting Interlayer , 2012 .

[30]  Meng Li,et al.  Planar perovskite solar cells with 15.75% power conversion efficiency by cathode and anode interfacial modification , 2015 .

[31]  M. Li,et al.  Seed-mediated superior organometal halide films by GeO2 nano-particles for high performance perovskite solar cells , 2016 .

[32]  A. Jen,et al.  High‐Performance Planar‐Heterojunction Solar Cells Based on Ternary Halide Large‐Band‐Gap Perovskites , 2015 .

[33]  Rui Zhu,et al.  Engineering of electron-selective contact for perovskite solar cells with efficiency exceeding 15%. , 2014, ACS nano.

[34]  Michael Grätzel,et al.  Tris(2-(1H-pyrazol-1-yl)pyridine)cobalt(III) as p-type dopant for organic semiconductors and its application in highly efficient solid-state dye-sensitized solar cells. , 2011, Journal of the American Chemical Society.

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

[36]  Sang Il Seok,et al.  Voltage output of efficient perovskite solar cells with high open-circuit voltage and fill factor , 2014 .

[37]  Namchul Cho,et al.  High‐Performance and Environmentally Stable Planar Heterojunction Perovskite Solar Cells Based on a Solution‐Processed Copper‐Doped Nickel Oxide Hole‐Transporting Layer , 2015, Advanced materials.

[38]  S. Rutter,et al.  A Novel Oligomer as a Hole Transporting Material for Efficient Perovskite Solar Cells , 2015 .

[39]  Wei Chen,et al.  Efficient and stable large-area perovskite solar cells with inorganic charge extraction layers , 2015, Science.

[40]  M. Grätzel,et al.  A simple 3,4-ethylenedioxythiophene based hole-transporting material for perovskite solar cells. , 2014, Angewandte Chemie.

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

[42]  L. Liao,et al.  Improved hole interfacial layer for planar perovskite solar cells with efficiency exceeding 15%. , 2015, ACS applied materials & interfaces.

[43]  Jenny Nelson,et al.  Nondispersive hole transport in amorphous films of methoxy-spirofluorene-arylamine organic compound , 2003 .

[44]  L. Liao,et al.  Origin of enhanced electrical and conducting properties in pentacene films doped by molybdenum trioxide , 2013 .

[45]  Yongbo Yuan,et al.  Non-wetting surface-driven high-aspect-ratio crystalline grain growth for efficient hybrid perovskite solar cells , 2015, Nature Communications.

[46]  Steffen Meyer,et al.  Copper(I) Iodide as Hole‐Conductor in Planar Perovskite Solar Cells: Probing the Origin of J–V Hysteresis , 2015 .

[47]  Steffen Meyer,et al.  Degradation observations of encapsulated planar CH3NH3PbI3 perovskite solar cells at high temperatures and humidity , 2015 .

[48]  Michael Grätzel,et al.  Nanostructured TiO2/CH3NH3PbI3 heterojunction solar cells employing spiro-OMeTAD/Co-complex as hole-transporting material , 2013 .

[49]  Martin Pfeiffer,et al.  Interface electronic structure of organic semiconductors with controlled doping levels , 2001 .

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

[51]  H. Lee,et al.  Polyfluorene Derivatives are High‐Performance Organic Hole‐Transporting Materials for Inorganic−Organic Hybrid Perovskite Solar Cells , 2014 .

[52]  Jeroen van den Brink,et al.  The quantum nature of skyrmions and half-skyrmions in Cu2OSeO3 , 2014, Nature Communications.

[53]  Qi Chen,et al.  Improved air stability of perovskite solar cells via solution-processed metal oxide transport layers. , 2016, Nature nanotechnology.

[54]  Xudong Yang,et al.  Hybrid interfacial layer leads to solid performance improvement of inverted perovskite solar cells , 2015 .

[55]  Sang Il Seok,et al.  Effective Electron Blocking of CuPC‐Doped Spiro‐OMeTAD for Highly Efficient Inorganic–Organic Hybrid Perovskite Solar Cells , 2015 .

[56]  M. Li,et al.  High Efficiency Pb–In Binary Metal Perovskite Solar Cells , 2016, Advanced materials.

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

[58]  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.

[59]  Cheng Bi,et al.  Doped hole transport layer for efficiency enhancement in planar heterojunction organolead trihalide perovskite solar cells , 2015 .

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

[61]  M. Li,et al.  Induced Crystallization of Perovskites by a Perylene Underlayer for High-Performance Solar Cells. , 2016, ACS nano.