  The need to reduce the environmental impact of inorganic electronic systems
is pressing. Although the field of organic electronics provides a potential
solution to this issue, research and optimization is still majorly carried out
on glass or plastic substrates. Additionally, the fabrication of organic
devices requiring transparent electrodes is fraught with complex techniques and
expensive materials which limit widespread implementation and sustainability
goals. Here, we show that the quasi-fractal lignocellulose structures extracted
from natural leaves can be successfully modified to be used as biodegradable
substrates as well as electrodes for optoelectronic applications. Chemically
coating the microstructures of these leaf skeletons with metals results in
quasi-transparent, flexible electrodes having sheet resistances below 1 ohm/sq.
and a concomitant current carrying capacity as high as 6 A over a 2.5*2.5 cm2
leaf electrode, all while maintaining broadband optical transmittance values of
around 80%.
