Large-scale full-solution, vacuum-free gravure printed ITO-free flexible organic solar cells

Bachelorarbeit , 2014 , 100 Seiten , Note: 1,0

Technik

This bachelor thesis presents the fabrication and evaluation of large-scale full-solution roll-to-roll processed, ITO-free flexible organic solar cells in a modified inverted device geometry by gravure printing on a discrete laboratory-scale printing system.
The layer stack is based on flexible PET substrate whereupon the back silver cathode was printed on top. The electron transport layer of ZnO and a double light absorbing photoactive layer of P3HT:PCBM, the hole transport layer of PEDOT:PSS and front silver anode were printed consecutively. All layers were roll-to-roll gravure printed from solution under full ambient vacuum-free conditions at a web speed of 2 m min−1. The completed solar cells were characterized by J-V and comprising layers by light beam induced current measurements. For fast testing and reproducibility experiments the remaining layers of the stack after each gravure printed film were deposited by slot-die coating and flexographic printing on a single roll coating system. Unfortunately functional organic solar cells of a fully gravure printed layer stack could not be found. A power conversion efficiency of 0.15 % of partly roll-to-roll gravure printed and residuary roll-based slot-die coated and flexographic printed organic solar cells under AM1.5G illumination was obtained.

The thesis contains a brief introduction in the topic of renewable energies and organic photovoltaic followed by the state of art in two-dimensional gravure printing organic solar cells and the motivation to particularly foreground this fabrication method. In the fundamentals part the working principle, device geometries, affiliated by the concept of ITO-free organic solar cells and materials in an organic photovoltaic device including characterization methods are presented.

Afterwards large-scale manufacturing techniques of organic photovoltaic comprising coating and printing technologies are reviewed and the roll-to-roll manufacturing strategies are introduced. In the experimental part the design, machinery and equipment used and fabrication of gravure printed flexible organic solar cell are chronologically described in detail in connection with presenting and discussing the results after characterizing the completed solar cells. Challenges that were faced during the studies are described subsequently and solutions of appeared problems are presented. A conclusion and outlook finalizes the thesis.

Inhaltsverzeichnis

• Introduction
  • The need for solar energy
  • Generations of solar cell technology
  • Research fields of organic solar cells
• State of art and motivation
• Fundamentals
  • Working principle of OPV device
  • Device geometries of OPV device
  • ITO-free OPV device
  • Materials in OPV device
    • J-V curve
    • LBIC
  • Large-scale manufacturing methods for OPV
    • Coating technologies
      • Slot-die coating
      • Blade coating
      • Spray coating
    • Printing technologies
      • Screen printing
      • Gravure printing
      • Flexographic printing
      • Inkjet printing
    • Summary of coating and printing techniques
    • R2R concept and manufacturing strategies
• Experimental
  • Gravure printing of silver back cathode
  • Gravure printing of ZnO
  • Gravure printing of active layer
  • Gravure printing of PEDOT:PSS
  • Gravure printing of silver front anode
  • Deposition of remaining layers
  • Characterization
• Results and discussion
  • Gravure printed silver back cathode
  • Gravure printed ZnO
  • Gravure printed active layer
  • Gravure printed PEDOT:PSS
  • Gravure printed silver front anode
  • Summary of results
• Challenges
• Conclusion and outlook
• Bibliography

Zielsetzung und Themenschwerpunkte

This bachelor thesis aims to investigate the fabrication and evaluation of large-scale, full-solution, roll-to-roll processed, ITO-free flexible organic solar cells in a modified inverted device geometry by gravure printing on a discrete laboratory-scale printing system. The thesis explores the feasibility of using gravure printing for the production of flexible organic solar cells, focusing on the challenges and opportunities associated with this approach.

• Fabrication and characterization of large-scale, flexible organic solar cells using gravure printing.
• Evaluation of the performance and efficiency of gravure-printed organic solar cells.
• Investigation of the challenges and limitations of gravure printing for organic solar cell fabrication.
• Exploration of potential solutions to overcome the challenges encountered during the fabrication process.
• Analysis of the potential of gravure printing for the large-scale production of flexible organic solar cells.

Zusammenfassung der Kapitel

The introduction provides a comprehensive overview of the need for solar energy, the evolution of solar cell technology, and the research fields of organic solar cells. It highlights the importance of developing efficient and cost-effective solar energy technologies to address the growing global energy demand.

The state of art and motivation section reviews the current advancements in the field of two-dimensional gravure printing of organic solar cells. It emphasizes the advantages of gravure printing for large-scale production and its potential to overcome the limitations of conventional fabrication methods.

The fundamentals chapter delves into the working principle of organic photovoltaic (OPV) devices, exploring different device geometries, the concept of ITO-free OPV devices, and the materials used in OPV devices. It also discusses characterization methods, including J-V curve and LBIC measurements, used to evaluate the performance of OPV devices.

The experimental section provides a detailed description of the design, machinery, and equipment used in the fabrication of gravure-printed flexible organic solar cells. It outlines the chronological steps involved in the printing process, from the gravure printing of the silver back cathode to the deposition of the remaining layers.

The results and discussion chapter presents the findings obtained from the characterization of the fabricated solar cells. It analyzes the performance of each printed layer, highlighting the challenges encountered and the solutions implemented. The chapter also summarizes the overall results and discusses the potential of gravure printing for the production of high-performance organic solar cells.

The challenges section focuses on the difficulties faced during the fabrication process, including issues related to layer uniformity, adhesion, and device performance. It explores potential solutions to overcome these challenges and improve the overall efficiency of the gravure printing process.

Schlüsselwörter

The keywords and focus themes of the text encompass large-scale, full-solution, roll-to-roll processed, ITO-free flexible organic solar cells, gravure printing, device geometry, inverted device, layer stack, characterization, J-V curve, LBIC, performance, efficiency, challenges, and solutions. The thesis explores the feasibility of using gravure printing for the production of flexible organic solar cells, focusing on the challenges and opportunities associated with this approach.

• Hochschule: Friedrich-Alexander-Universität Erlangen-Nürnberg
• Veranstaltung: Nanotechnologie
• Note: 1,0
• Autor: Johannes Michael Küffner (Autor:in)
• Erscheinungsjahr: 2014
• Seiten: 100
• Katalognummer: V287304
• ISBN (eBook): 9783656875512
• ISBN (Buch): 9783656875529
• Sprache: Englisch
• Schlagworte: Nanotechnologie, organic, organic solar cells, solar cell, solar cells, gravure, gravure printing, printing, nanotechnology, full-solution, vacuum-free, ITO-free, flexible, Solarzelle, Organisch, organische Solarzelle