Optimized Process of Fully Spray-Coated Organic Solar Cells on Woven Polyester Cotton Fabrics

This paper presents the novel use of spray coating to fabricate organic solar cells on fabrics for wearable energy harvesting applications and optimises photovoltaic efficiency. A fully spray coated photovoltaic (PV) device fabricated on fabric has been successfully demonstrated with comparable power conversion efficiency to glass based counterparts. All the PV devices are characterised under AM 1.5 (100mW/cm2) irradiation using an ABET solar simulator. Device morphologies are examined by scanning electron microscopy (SEM). The aim of this study is to develop and optimise a method to obtain reproducible photovoltaic textiles using a fully spray coating processing at low temperature (<150 °C) on a standard 65/35 polyester cotton fabric. The main challenge when spray coating solar cells of less than a few micron thickness is the surface roughness of the polyester cotton fabric which is of the order of 150 µm. We report a maximum optimised efficiency of 2.7% achieved on a glass substrate and 0.02% on woven fabrics, respectively. This approach is suitable for the low cost integration of PV devices into clothing and other decorative textiles.