Techniques to Achieve Stretchable Photovoltaic Devices from Physically Non-Stretchable Devices through Chemical Thinning and Stress-Releasing Adhesive

摘要

Integration of photovoltaic devices on the deformable surfaces of plantsand animals is challenging, as most of the photovoltaic devices possess nostretchability which severely restricts the underneath deformable substratesand causes potential delamination of the devices from the substrates dueto large shear stress. Here, techniques to achieve stretchable photovoltaicdevices through chemically thinning flexible solar cells and intermediate hard–soft transition layers are proposed. The resulting photovoltaic devices areonly 25 μm in thickness with a radius of curvature of 1 mm, offering excellentadaptability to leaves and many curved surfaces. The intermediate layer thatis based on silicone adhesive with low modulus provides an interface betweennon-stretchable photovoltaic devices and deformable substrates, resulting ina stretchability of the overall structures larger than 140. Key parameters ofthe photovoltaic device such as open-circuit voltage, short circuit current, fillfactor, and conversion efficiency indicate the excellent performance of thinneddevices. Potential applications of ultra-thin photovoltaic devices in energyharvesting and light intensity sensing on stretchable substrates are demonstrated,suggesting the practical use of the devices in constructing stretchableself-powered wearable systems for agriculture and healthcare monitoring.