Highly Stretchable Photovoltaic Module with Improved Mechanical Robustness through Elastomeric Interconnections

Abstract

Stretchable photovoltaics have garnered increasing attention due to their adaptability to various surfaces and applications, meeting the rising demands for portable and flexible power sources. Herein, stretchable solar modules are demonstrated by sandwiching electrically connected rigid solar cells between top and bottom polydimethylsiloxane (PDMS) layers, which are then attached onto an elastomer with an island and trench structure. The electrical connection of solar cells is achieved by dispenser printing of electrically conductive adhesive (ECA). The fabricated stretchable solar modules have a maximum biaxial elongation of 75%, and the electrical connection of the solar cells using ECA results in a negligible efficiency loss of 1.6%. In particular, embedding of solar cells and interconnects between PDMS layers enhances mechanical stability by placing these key components at the mechanical neutral plane and the long-term stability against humidity due to the encapsulation role of the PDMS layer. The module demonstrates only a 5% of efficiency drop after 1000 hours in the dump-heat test (85 degrees C/85%). The results in this study are not limited to solar cells but can be applied to various types of rigid devices, paving the way for the commercialization of stretchable electronics. Photo of a stretchable module on spherical surface consisting of 25-unit (5 x 5) solar cells integrated onto a hemisphere and its photovoltaic characteristics and biaxial stretchability.image (c) 2024 WILEY-VCH GmbH