High Efficiency Stretchable (Highly Conformable) Photovoltaics for Expeditionary Forces

The next generation of photovoltaic systems need to meet both physical (shape, size, packaging, durability) and electronic (efficiency, stability) requirements of applications that are not possible to implement today. One of these requirements is to be able to stretch electronic devices without sacrificing the performance and lifetime. Commercially available photovoltaics that incorporate thin semiconductor films on plastic or thin metal substrates are sufficiently flexible and lightweight to be rolled up for easy transport. Unrolled, the photovoltaic systems are planar and not highly deformable. We propose a design and fabrication method for the manufacturing of stretchable and flexible photovoltaic system based on Cu(InGa)Se2 technology with higher efficiencies than silicon based counterparts. Cu(InGa)Se2 based solar cells have often been touted as being among the most promising of solar cell technologies for cost effective power generation. This is partly due to the advantages of thin films for low cost, high rate semiconductor deposition over large areas using layers only a few microns thick and for fabrication of monolithically interconnected modules. Our design is based on fabrication of Cu(InGa)Se2 thin-films on stretchable substrates using commercially available deposition tools.