Substrates for flexible electronics: A practical investigation on the electrical, film flexibility, optical, temperature, and solvent resistance properties

• Published in: Journal of polymer science. Part B, Polymer physics Vol. 49; no. 9; pp. 638 - 648
• Main Authors: Zardetto, Valerio, Brown, Thomas M, Reale, Andrea, Di Carlo, Aldo
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01.05.2011; Wiley
• Subjects: Applied sciences; Corrosion resistance; deformation; Devices; Electronics; Exact sciences and technology; Flexibility; flexible films; Forms of application and semi-finished materials; Glass; indium; Indium tin oxide; indium tin oxide (ITO); Materials; polyethylene; polyethylene naphthalate (PEN); polyethylene teraphthalate (PET); Polyethylene terephthalates; Polymer industry, paints, wood; Reproduction; Sheets and films; solvents; stainless steel; substrates; Technology of polymers; temperature; tin; titanium; ultraviolet radiation; Ethylene terephthalate polymer; Transparency; Thermal strain; Electrical properties; polyethylene teraphthalate (PET); flexible films; Ester polymer; Temperature effect; Experimental study; Plastic film; Solvent resistance; Substrate; Ultraviolet resistance; polyethylene naphthalate (PEN); Sheet resistivity; Thiophene derivative polymer; Ethylenedioxythiophene polymer; Optical properties; Styrenesulfonate polymer; indium tin oxide (ITO); substrates; Doped polymer; ITO layers; Comparative study
• ISSN: 0887-6266; 1099-0488; 1099-0488
• DOI: 10.1002/polb.22227

Designing and developing flexible electronics requires a thorough investigation of the substrates available for the fabrication of devices. Here, we present a practical study on a variety of significant substrates: polyethylene terephthalate (PET), its heat-stabilized (HS) derivative, HS-PET, and polyethylene naphthalate (PEN) plastic insulating films; indium tin oxide (ITO)-coated ITO/PEN and ITO/PET transparent conducting films; rigid ITO/glass and FTO/glass substrates; stainless steel and titanium foils. We put the substrates through a range of tests these actually undergo during device fabrication to determine their optical, mechanical flexibility (under different types of tensile and compressive stress bending with and without a PEDOT:PSS conducting polymer layer), solvent resistance, stability to temperature treatment (conductivity and deformation), and to UV irradiation. We highlight issues and propose solutions to improve substrate response. The results and thresholds extracted reveal limitations and windows of opportunity useful for the designer of flexible optoelectronics in determining manufacturing processes and the final applications under everyday operation.