Inkjet Printed Flexible and Free Design OPV Modules for Indoor Application

Inkjet printing is a unique coating and printing technique. Fully digital, it allows to print design with a large variety of shape and dimensions. Drop on Demand technology induces low material waste. Moreover, it presents the advantage to be maskless and contactless allowing to avoid any contamination during the deposition of the thin layers. Thus, it caught the printed electronic community attention and more especially the one of the Organic Photovoltaic (OPV) field. In this context and due to the mechanical flexibility, light weight, aesthetics, absorption tunability and environmental friendliness, OPV have superior application potential over their inorganic and hybrid counterparts. In 2004, V. Shah et al. printed the first OPV active layer by inkjet printing. Although the power conversion efficiency is very low (< 0,1%)1 this is the first proof of concept of the feasibility to use inkjet printing for OPV fabrication. The first efficient active layer printed by inkjet printing is made three years later2 and the first OPV fully printed by inkjet printing is obtained only in 20143,4.
To achieve efficient inkjet printed indoor OPV cells and modules, we show that each OPV layer must be carefully optimized, and several key parameters should be finely tuned. However, inkjet printed devices are often made at laboratory scale with small printers and halogenated solvents. To be competitive at industrial scale, OPV modules should be made in air from green solvents with large scale printhead. Herein we demonstrate the challenge to go from academic lab-scale (spin-coating under inert atmosphere, small cell) to industrial scale (inkjet printing in
air, modules).
To prove the great advantage of inkjet printing as a digital technology allowing freedom of forms and designs, OPV modules with different artistic shapes are demonstrated keeping high performance under indoor conditions and allowing better integration into IoT Products. Reported results confirm that inkjet printing has high potential for the processing of indoor OPV, allowing quick changes in design as well as in materials.