Project Acronym DigiPRINT
Project Title Large Area High Resolution Digital Printing for Organic Thin Film Transistor Fabrication
Project Start Date 01 Dec 2012
Project Duration 24 months
Partners’ names and countries Oxford Lasers Ltd, UK
Centre for Process Innovation, UK
Sensofar, Catalonia
Universitat de Barcelona, Catalonia

Project Coordinator:

Name: Dr Dimitris Karnakis

Organization: Oxford Lasers Ltd

E-mail: dimitris.karnakis@oxfordlasers.com

Project DigiPRINT explored low temperature, maskless digital fabrication of organic thin-film transistors (OTFTs) on large area substrates. Both “laser-assisted” inkjet printing (IJ) and “laser-induced forward transfer (LIFT)” of functional materials were investigated. The project developed: (i) large area high resolution (<10μm) printing by laser-assisted IJ and LIFT of functional OTFT materials, (ii) low leakage fast switching OTFT by laser direct-write selective layer nanopatterning (10^6 on/off ratio at high mobility), (iii) high resolution defect repair of (mis)printed lines (10μm) by digital laser transfer combining LIFT and laser sintering and (iv) non-contact surface metrology tools for online quality control suitable for high volume roll-to-roll processing. The novelty in the project stemmed from the intelligent use of advanced and industrially robust ultrafast DPSS lasers combined with real-time monitoring of deposition and patterning processes by in-situ surface characterisation with non-contact optical metrology heads. Novel OTFT materials where especially formulated to match IJ and laser patterning requirements. The developed technology is R2R compatible and a laser prototype was designed integrating the optical metrology tools, laser microstructuring, laser transfer and laser curing modules.