Synthesis and Effect of the Structure of Bithienyl-Terminated Surfactants for Dielectric Layer Modification in Organic Transistor

A series of bithienyl-terminated surfactants with various alkyl chain lengths (from C8 to C13) and phosphono or chlorodimethylsilyl anchoring groups were synthesized by palladium-catalyzed hydrophosphonation, or platinum-catalyzed hydrosilylation as a key step. Surfactants were tested in pentacene or α-sexithiophene-based organic field-effect transistors (OFETs) for the modification of the dielectric surface. The studied surfactants increased the effective mobility of the α-sexithiophene-based device by up to one order of magnitude. The length of alkyl chain showed to be significant for the pentacene-based device, as the effective mobility only increased in the case of dielectric modification with bithienylundecylphosphonic acid. AFM allowed a better understanding of the morphology of semiconductors on bare SiO2 and surfaces treated with bithienylundecylphosphonic acid

Increased colloidal stability and decreased solubility-sol-gel synthesis of zinc oxide nanoparticles with humic acids

Adding the humic acid coating to the nanoparticles of zinc oxide (ZnO-NP) may improve the properties necessary for their colloidal stability. To show how humic acid coating affects the properties of ZnO-NP, three differently sol-gel synthesized ZnO-NP were synthesized: pristine zinc oxide nanoparticles without coating (p-ZnO-NP) and humic acid coated zinc oxide nanoparticles at two different initial concentrations of 20 mg/L (HA20-ZnO-NP) and 200 mg/L (HA200-ZnO-NP) of humic acids in the starting solution. All ZnO-NP were found to be nanocrystals of mineral zincite exhibiting wurtzite crystal symmetry. Transmission electron microscopy showed that capping by humic acids during synthesis decreased the size of HA20-ZnO-NP and HA200-ZnO-NP compared to p-ZnO-NP nanoparticles. Via experiments, HA20-ZnO-NP were found to dissolve less and have a similar or higher stability than both p-ZnO-NP and HA200-ZnO-NP.Web of Science1953030302