An aqueous solution-processed CuOX film as an anode buffer layer for efficient and stable organic solar cells

A facile and green method has been developed for the aqueous solution preparation of CuOX as an anode buffer layer for organic solar cells (OSCs). The CuOX buffer layer is prepared simply by spin-coating a copper acetylacetonate precursor based aqueous solution onto an ITO substrate at room temperature in ambient air. Hydrogen peroxide (H2O2) is used to modify the precursor aqueous solution and can greatly increase the work function of the CuOX film to improve the hole collection efficiency and the charge transport efficiency. UV-ozone post-treatment of the CuOX film leads to the fully oxidized state of copper oxide, which significantly improves the performance of OSCs. Through H2O2 modification and UV-ozone post-treatment on the CuOX anode buffer layer, the highest power conversion efficiency of the OSCs based on PTB7:PC71BM blends reaches 8.68%, which is 10% higher than that of the standard PEDOT:PSS anode buffer layer based OSCs. In addition, the devices with the CuOX buffer layer show much better air stability than those with PEDOT:PSS. Our results indicate that the aqueous solution processed CuOX with low cost and green solvents is a promising anode buffer layer material for efficient and stable OSCs.

[1]  Thomas Riedl,et al.  Low-temperature, solution-processed MoO(x) for efficient and stable organic solar cells. , 2012, ACS applied materials & interfaces.

[2]  Yongfang Li,et al.  Single‐Junction Polymer Solar Cells Exceeding 10% Power Conversion Efficiency , 2015, Advanced materials.

[3]  William R. Salaneck,et al.  Energy‐Level Alignment at Organic/Metal and Organic/Organic Interfaces , 2009 .

[4]  Alex K.-Y. Jen,et al.  High‐Efficiency Polymer Solar Cells Achieved by Doping Plasmonic Metallic Nanoparticles into Dual Charge Selecting Interfacial Layers to Enhance Light Trapping , 2013 .

[5]  S. Kirchmeyer,et al.  Scientific importance, properties and growing applications of poly(3,4-ethylenedioxythiophene) , 2005 .

[6]  Paul Heremans,et al.  Influence of cathode oxidation via the hole extraction layer in polymer:fullerene solar cells , 2011 .

[7]  D. Ginley,et al.  Enhanced Efficiency in Plastic Solar Cells via Energy Matched Solution Processed NiOx Interlayers , 2011 .

[8]  A. Heeger,et al.  Improved light harvesting and improved efficiency by insertion of an optical spacer (ZnO) in solution-processed small-molecule solar cells. , 2013, Nano letters.

[9]  F. Krebs,et al.  Roll-coating fabrication of ITO-free flexible solar cells based on a non-fullerene small molecule acceptor , 2015 .

[10]  Yongfang Li,et al.  Efficient and stable polymer solar cells with solution-processed molybdenum oxide interfacial layer , 2013 .

[11]  A. Heeger,et al.  25th Anniversary Article: Bulk Heterojunction Solar Cells: Understanding the Mechanism of Operation , 2014, Advanced materials.

[12]  Yongfang Li,et al.  Solution‐Processed Rhenium Oxide: A Versatile Anode Buffer Layer for High Performance Polymer Solar Cells with Enhanced Light Harvest , 2014 .

[13]  M. J. Tan,et al.  Air-stable efficient inverted polymer solar cells using solution-processed nanocrystalline ZnO interfacial layer. , 2013, ACS applied materials & interfaces.

[14]  Jian-guo Tang,et al.  Simple solution-processed CuOX as anode buffer layer for efficient organic solar cells , 2015 .

[15]  Yongfang Li,et al.  Solution-processed vanadium oxide as a hole collection layer on an ITO electrode for high-performance polymer solar cells. , 2012, Physical chemistry chemical physics : PCCP.

[16]  Ching-Fuh Lin,et al.  Sol–gel processed CuOx thin film as an anode interlayer for inverted polymer solar cells , 2010 .

[17]  He Yan,et al.  Aggregation and morphology control enables multiple cases of high-efficiency polymer solar cells , 2014, Nature Communications.

[18]  Hongzheng Chen,et al.  Recent advances in plasmonic organic photovoltaics , 2015, Science China Chemistry.

[19]  T. Alford,et al.  P3HT: PC61BM based solar cells employing solution processed copper iodide as the hole transport layer , 2015 .

[20]  Alex K.-Y. Jen,et al.  Recent progress and perspective in solution-processed Interfacial materials for efficient and stable polymer and organometal perovskite solar cells , 2015 .

[21]  Kuei-Hsien Chen,et al.  Effect of copper oxide oxidation state on the polymer-based solar cell buffer layers. , 2014, ACS applied materials & interfaces.

[22]  F. Krebs,et al.  Roll-coating fabrication of flexible large area small molecule solar cells with power conversion efficiency exceeding 1% , 2014 .

[23]  Ying-Ying Zhang,et al.  Ultra-stable two-dimensional MoS2 solution for highly efficient organic solar cells , 2014 .

[24]  L. Tjeng,et al.  Electronic structure of Cu2O and CuO. , 1988, Physical review. B, Condensed matter.

[25]  Ikerne Etxebarria,et al.  Solution-processable polymeric solar cells: A review on materials, strategies and cell architectures to overcome 10% , 2015 .

[26]  T. Riedl,et al.  Solution Processed Vanadium Pentoxide as Charge Extraction Layer for Organic Solar Cells , 2011 .

[27]  R. Friend,et al.  Built-in field electroabsorption spectroscopy of polymer light-emitting diodes incorporating a doped poly(3,4-ethylene dioxythiophene) hole injection layer , 1999 .

[28]  Zhan'ao Tan,et al.  High-performance polymer solar cells with solution-processed and environmentally friendly CuOx anode buffer layer. , 2013, ACS applied materials & interfaces.

[29]  Zhan'ao Tan,et al.  Solution-processable metal oxides/chelates as electrode buffer layers for efficient and stable polymer solar cells , 2015 .

[30]  Shijun Jia,et al.  Polymer–Fullerene Bulk‐Heterojunction Solar Cells , 2009, Advanced materials.

[31]  Cristian Ionescu-Zanetti,et al.  Semiconductive Polymer Blends: Correlating Structure with Transport Properties at the Nanoscale , 2004 .

[32]  Yingying Fu,et al.  Sonochemistry-synthesized CuO nanoparticles as an anode interfacial material for efficient and stable polymer solar cells , 2015 .

[33]  E. E. Carpenter,et al.  Preparation of Elemental Cu and Ni Nanoparticles by the Polyol Method: An Experimental and Theoretical Approach , 2011 .

[34]  Sung-Hwan Han,et al.  Performance and stability of electroluminescent device with self-assembled layers of poly(3,4-ethylenedioxythiophene)–poly(styrenesulfonate) and polyelectrolytes , 2006 .

[35]  C. Jin,et al.  Engineering crystalline structures of two-dimensional MoS2 sheets for high-performance organic solar cells , 2014 .

[36]  Yongfang Li,et al.  Efficient polymer solar cells with a solution-processed and thermal annealing-free RuO2 anode buffer layer , 2014 .

[37]  Fei Huang,et al.  Inverted polymer solar cells with 8.4% efficiency by conjugated polyelectrolyte , 2012 .

[38]  N. Armstrong,et al.  Selective Interlayers and Contacts in Organic Photovoltaic Cells. , 2011, The journal of physical chemistry letters.

[39]  Yongfang Li,et al.  Solution-Processed Tungsten Oxide as an Effective Anode Buffer Layer for High-Performance Polymer Solar Cells , 2012 .

[40]  Yu-Shan Cheng,et al.  Single Junction Inverted Polymer Solar Cell Reaching Power Conversion Efficiency 10.31% by Employing Dual-Doped Zinc Oxide Nano-Film as Cathode Interlayer , 2014, Scientific Reports.