200 nm Ultrathin Freestanding Organic Photovoltaics

Ultrathin organic photovoltaics (OPVs) have great application prospects in the field of wearable electronics, such as electronic tattoos, electronic skins, etc. In this study, we report substrate-free ultrathin OPVs with a thickness of approximately 200 nm. The freestanding OPV devices achieve a power conversion efficiency of 11.6% and a power-per-weight ratio of 109.4 W g^-1, with a weight of 1.06 g m^-2. The ultrathin OPVs can self-adhere to various surfaces with complex and curved structures, ensuring excellent conformity. Notably, the ultrathin OPV devices demonstrate remarkable mechanical flexibility, maintaining 90% of their initial power conversion efficiency after 1000 compression-stretching cycles and are capable of bending to a radius of less than 2 μm. These attributes make ultrathin OPVs a crucial advancement in expanding the application landscape for wearable electronics and other special applications with ultraflexible and ultralight requests.