Generation of ultrathin,
transferable, and imperceptible electronic
devices [e.g., organic photodiode (OPD)] for multiple applications,
such as personalized health monitors and wearables, is emerging due
to the continuous development of materials and manufacturing processes.
For such devices, the choice of a suitable substrate is of utmost
importance. A water decal transfer from a temporary tattoo paper is
adopted here as a substrate for ultrathin and conformable organic
components because of easy and reliable transfer of a ≈600
nm robust and transparent polymer nanofilm of ethyl cellulose. Strategies
for the fabrication of a transferable OPD on a temporary tattoo are
investigated. A device with an overall thickness <1 μm and
its performance after transfer are demonstrated. Then, efforts are
put into fabricating an OPD by inkjet printing with a water-soluble
active layer consisting of polythiophene and fullerene derivatives
to aid cost- and material-efficient, large-scale production possibilities.
Additionally, a second semitransparent electrode made of printed aluminum-doped
zinc oxide and silver nanowires is used to allow usage from both sides
to enhance the application potential. Both OPD examples presented
here need improvement of the device performance but permitted us to
highlight the versatility and application potential of temporary tattoos
for transferable components. Target surfaces for the final application
after transfer include artificial (flat and smooth, e.g., glass, or
even complex and rough, e.g., concrete, paper, and so forth) as well
as natural ones.