High-Quality Solution-Processed Metal-Oxide Gate Dielectrics Realized With a Photo-Activated Metal-Oxide Nanocluster Precursor

High-quality solution-derived amorphous alumina (a-Al2O3) dielectric has been achieved with [Al13(μ3-OH)6(μ-OH)18(H2O)24](NO3)15(Al-13 nanocluster) as a precursor and a local structure-controllable activation process via deep-UV-induced photochemical activation. The synergetic combination of an Al-13 nanocluster precursor and high-energetic photochemical activation enables the formation of highly dense a-Al2O3thin films via an efficient dissociation and rearrangement of the nanocluster skeleton. The electrical characteristics of the nanocluster-based a-Al2O3thin films were investigated in terms of their operative electronic conduction mechanism by comparing conventional nitrate-based and vacuum-deposited films. From these results, it was found that the leakage current density of solution-processed a-Al2O3layers is largely affected by their precursor structures. Finally, to demonstrate the versatility of the high-quality nanocluster-based a-Al2O3dielectrics, carbon nanotube and metal-oxide thin-film transistors were fabricated on low thermal budget stretchable and rigid substrates, respectively.