Excimer laser annealing of ZnO nanoparticles for thin film transistor fabrication

Abstract

Nanoparticle solutions are considered promising for realizing low cost printable high performance flexible electronics. In this paper, excimer laser annealing (ELA) was employed to induce melting of solution-deposited ZnO nanoparticles and form electrical conductive porous films. The properties of the films were characterized by scanning electron microscopy, high-resolution TEM, Hall-effect, and photoluminescence measurements. Thin film field effect transistors have been fabricated by ELA without the use of conventional vacuum or any high temperature thermal annealing processes. The transistors show n-type accumulation mode behavior with mobility greater than 0.1 cm2/V-s and current on/off ratios of more than 104. Optimization and control of the laser processing parameters minimized thermal impact on the substrate. This technique can be beneficial in the fabrication of metal oxide based electronics on heat sensitive flexible plastic substrates using low-cost, large-area solution processing combined with direct printing techniques.