LAFLEXEL – Laser Annealing for improved FLEXible Electronics

The LAFLEXEL project aims to deliver high performance metal-oxide thin‐film transistors (TFTs) by introducing a photonic process, namely laser annealing. Laser annealing an ultra-fast and macroscopically cold process which avoids the harmful effect of thermal processing and can thus be used in conjunction with temperature sensitive substrates - for example, when treating components built onto polymeric substrates.  A laser beam is moved and manipulated rapidly to process large areas, while maintaining high spatial resolution for selective patterning / annealing. The proposed process can significantly enhance performance and reduce costs for high-tech applications by offering precise control, robustness, extended lifetime, high capacity and lower consumable expenses.

Project Objectives

• Identify the most appropriate laser annealing system design and processing parameters.
• Investigate facile optimisation of the process conditions using systems to meticulously vary parameters, including fluence, number of pulses, wavelength, environmental parameters (pressure, chemical composition) and temperature of the substrate.

Key Achievements

  • Fabricated indium oxide-based TFTs, prepared by spin-coating - in collaboration with Imperial College London.
    • Metal oxide conversion was confirmed, excimer laser annealing (ELA) changed electrical characteristics in specific ares of the film, very low leakage current, good ON-OFF current ratio.
  • Fabricated indium zinc oxide transistors with similar performance but highly improved threshold voltage, compared to thermally annealed counterparts - in collaboration with University of Cambridge.
    • This mild thermal annealing process (two thermal annealing steps (at 120°C) separated by ELA) shows potential for preparation of oxide TFT devices on polymeric substrates.
  • Fabricated high performance a-IGZO (sputtered) TFTs on flexible substrates - in collaboration with PragmatIC Printing.
    • Improved performance of TFTs in terms of hysteresis and ON-OFF current ratio.


Further details about LAFLEXEL

Industrial Partner

Posted in Pathfinder.