High Efficiency Stretchable (Highly Conformable) Photovoltaics for Expeditionary Forces

Various high-efficiency thin-film photovoltaic (PV) materials have been applied to flexible substrates. These thin PV films are most often sputtered onto plastic or thin metal substrates, which are generally sufficiently flexible to be rolled up but are not highly deformable or stretchable. Amorphous silicon and thin silicon modules and their metal interconnects all rupture when stretched. Organic materials, which are stretchable, have not been demonstrated with the requisite efficiency. To address the need for high-efficiency stretchable PVs, a hybrid organic-inorganic PV will be manufactured using inkjet printing and solutions processing on a pre-strained substrate. The design will incorporate transparent inorganic interconnects, printed in stretchable patterns. These amorphous interconnect materials have been demonstrated to withstand the biaxial strain the application requires. To increase the PV array’s sensitivity beyond the spectral range of silicon and amorphous silicon, inorganic sensitizers will be introduced into the solar cell, and efficient charge transfer into the transparent inorganic matrix will be demonstrated, so that efficiency >12% can be achieved. In Phase I, the ability of the PV to reliably respond to high levels of repeated strain will be tested. A design process flow for high volume and low cost will be demonstrated using established manufacturing equipment.