RESEARCHERS from Japan have developed a nanoparticle ink that can be used with room-temperature printing processes.
Printing semiconductor devices could provide low-cost high performance flexible electronics that outperform amorphous silicon thin film transistors, helping move display technology forward.
Nanoparticle inks could provide the way forward, but normal nanoparticle inks have non-conductive ligands surrounding the nanoparticles. These molecules are introduced during synthesis for stabilising the particles. These ligands must be removed by annealing to make the ink conducting.
The researchers from the National Institute of Materials Science and Okayama University in Japan have now developed a nanoparticle ink that does not need annealing. They developed nanoparticles surrounded by planar aromatic molecules that allow charge transfer.
The gold nanoparticles had a resistivity of around 9 x 10-6 Ω cm – similar to pure gold. The researchers used the nanoparticle ink to print organic thin film transistors on a flexible polymer and a paper substrate at room temperature, producing devices with mobilities of 7.9 and 2.5 cm2 V-1 s-1 for polymer and paper respectively – figures comparable to IGZO devices.