Fabrication of ZnO thin films from nanocrystal inks

Anthony J. Morfa, Gary Beane, Benjamin Mashford, Birendra Singh, Enrico Della Gaspera, Alex Martucci, Paul Mulvaney

Research output: Contribution to journalArticleResearchpeer-review

25 Citations (Scopus)

Abstract

Zinc oxide nanocrystals were prepared in ethanol and spin-cast to form semiconductor nanocrystal thin films that were thermally annealed at temperatures between 100 and 800 °C. Particle size, monodispersity, and film porosity were determined by X-ray diffraction, ultraviolet-visible absorption spectroscopy, and spectroscopic ellipsometry, respectively. Film porosity rapidly decreased above 400 °C, from 32% to 26%, which coincided with a change in electronic properties. Above 400 °C, the ZnO electron mobility, determined from FET transfer characteristics, increased from 10-3 to 10-1 cm2 V s-1, while the surface resistivity, determined from electrical impedance, decreased from 107 to 10 3 ω m over the same temperature range. Below the densification point, nanoparticle core resistivity was found to increase from 104 to 106 ω m, which is caused by the increasing polydispersity in the quantized energy levels of the nanocrystals. From 100 to 800 °C, crystallite size was found to increase from 5 to 18 nm in diameter. The surface resistance was decreased dramatically by passivation with butane thiol.

Original languageEnglish
Pages (from-to)19815-19821
Number of pages7
JournalJournal of Physical Chemistry C
Volume114
Issue number46
DOIs
Publication statusPublished - 25 Nov 2010

Cite this