Contacts on polyester textile as a flexible substrate for solar cells

In the present work, the authors have studied conductive surfaces on polyester fabrics by using two types of commercially available conductive polymers; polyaniline and poly (3,4-ethylenedioxythiophene)-poly (styrenesulphonate) (PEDOT: PSS) with 100 nm aluminium thin film evaporated on top of the polymer so the fabric becomes a conductive substrate for inorganic thin film solar cells. Conductive polymer surfaces on woven polyester fabrics were obtained by knife-over-table coating technique. Surface resistivities for polyaniline and PEDOT: PSS coated fabrics were measured and found in the range of 400 × 10³ and 1 × 10³ Ω/□, respectively. Thermal stability tests were carried out to evaluate the effect of specific periods of heal treatment at different elevated temperatures on resistance of polymer coated conducting textiles. PEDOT: PSS exhibited better stability than panipol. According to long term tests, PEDOT: PSS coated samples showed improvement in conductivity over 3 days whereas panipol showed the opposite. Transmission Line Model tests were performed to measure aluminium/polymer contact resistances which were found to be 120 × 10³ Ω for polyaniline and about 46.3 Ω for PEDOT: PSS. Mechanical bending tests for aluminium/PEDOT: PSS/fabric samples showed that the polymer can maintain the conductivity of samples by bridging micro-cracks in the metal film.