Hot Embossing of Polymer Substrates for Thin Silicon Cell Applications

The use of polymer substrates for thin film solar cells is becoming an issue of great interest, as they facilitate monolithic interconnection of the cells to produce modules and can be used in continuous roll-to-roll processes. However, to reach high efficiencies of thin film silicon cells on polymer substrates, the development of efficient light confinement strategies has to be improved. In this work, hot embossing is used to produce a suitable surface morphology on PEN substrates. Three morphologies have been studied by using three selected masters. To evaluate the quality of the embossing, the morphology of the masters and that of the stamped PEN samples have compared. Finally, the stamped polymers have been covered with thin Ag and transparent conductive oxide (TCO) layers and whole reflectance experiments have been performed to asses the efficiency of the fabricated back reflectors