Organic electronics,
in particular organic photovoltaics,
have
gained widespread attention due to their unique properties such as
lightness, flexibility, and low cost. Thanks to some recent breakthroughs
in organic solar cells (OSCs) that exhibit power conversion efficiencies
(PCEs) approaching 20%, this technology is slowly making its way into
the market as a complementary solution to conventional photovoltaic
devices. OSCs are well suited for high-end smart applications, ranging
from building integration and Internet of Things to consumer electronics.
However, up to now, little attention has been devoted to the environmental
impact and sustainability of components and processes. It is thus
necessary to develop a new generation of eco-designed devices without
losing the level of performance. In this work, we report the fabrication
of efficient and stable solution-processed OSCs built on a free-standing
sodium alginate (SA) substrate. SA is a natural biodegradable polymer
derived from brown algae. It is low-cost, nontoxic, abundant, water-processable,
and easy to manipulate for the realization of homogeneous and transparent
foils. SA-based OSCs exhibit PCEs from 1.8 to 7.2% and can be disassembled
through a safe and sustainable biocatalyzed process, allowing selective
and almost entire recovery of precious metals, such as Au and Ag,
as well as the separation of all of the main components. This allows
us to minimize the production of e-waste, in accordance with the requirements
of sustainability and the circular economy.