Fabrication of solution-processed nitrogen-doped niobium zinc tin oxide thin film transistors using ethanolamine additives

In this study, we fabricated the nitrogen-doped NbZnSnO channel layers by using the sol-gel method. Monoethanolamine (MEA) was used as a nitrogen additive. From the XPS results, the concentration of oxygen vacancies changes as a function of MEA/Nb ratio. A NbZnSnO film with MEA/Nb of 0.2 shows the lowest amount of oxygen vacancies. TFT electrical performance also shows a device with an MEA/Nb ratio of 0.2 possesses a high carrier mobility (7.4 cm2 V−1s−1) and good bias stress stability. In addition, we also investigated the effect of the aging time of precursor solution on the electrical characteristics of the TFT. After adding MEA, the annealing temperature of the NbZnSnO channels can be reduced, pertaining to the acceleration of the hydrolysis and condensation reaction.