So far, organic semiconductors always suffered from a comparatively low carrier mobility and most viable flexible or stretchable electronics applications relied on the design of rigid functional islands with deformable interconnects (pre-stretched and wrinkled or meandering electrodes).
Here the researchers boosted the carrier mobility of a P3HT–nanofibrils (NFs)/PDMS (polydimethylsiloxane) composite organic semiconductor using low weight-concentrations of highly conductive metallic carbon nanotubes (m-CNTs) at its surface. The dopant m-CNTs were dry-transferred through a lamination/delamination process of the polymeric semiconductor on a glass substrate bearing the dispersed m-CNTs.
Their paper “Fully rubbery integrated electronics from high effective mobility intrinsically stretchable semiconductors” published in the Science Advances journal explains how the dry-transferred m-CNTs substantially enhance the effective carrier mobility of the semiconductor compound by offering “fast lanes” for the charge that shorten the transport distance within the channel (while not creating full-length percolated shortcuts throughout the polymer). At a weight concentration of 0.05 wt %, the m-CNT does not form a percolated network, the authors verified.
The dry transfer doping preserves the crystallinity of the P3HTs-NFs, the authors report, characterizing carrier effective mobility to about 9.76 cm2/V·s, several folds that of non-doped organic semiconductor composites. By contrast, mixing the m-CNT and P3HT in a solution phase would not lead to a high mobility semiconductor because the crystallinity of the P3HT-NFs would sharply, the article explains.