Structural and electrical characterization of ZnO films grown by spray pyrolysis and their application in thin-film transistors

George Adamopoulos, Aneeqa Bashir, William P. Gillin, Stamatis Georgakopoulos, Maxim Shkunov, Mohamed A. Baklar, Natalie Stingelin, Donal D.C. Bradley, Thomas D. Anthopoulos

Research output: Contribution to journalArticlepeer-review

92 Scopus citations

Abstract

The role of the substrate temperature on the structural, optical, and electronic properties of ZnO thin films deposited by spray pyrolysis using a zinc acetate precursor solution is reported. Analysis of the precursor compound using thermogravimentry and differential scanning calorimetry indicates complete decomposition of the precursor at around 350 °C. Film characterization using Fourier Transform Infrared Spectroscopy (FTIR), photoluminescence spectroscopy (PL), and ultraviolet-visible (UV-Vis) optical transmission spectroscopy suggests the onset of ZnO growth at temperatures as low as 100 °C as well as the transformation to a polycrystalline phase at deposition temperatures >200 °C. Atomic force microscopy (AFM) and X-ray diffraction (XRD) reveal that as-deposited films exhibit low surface roughness (rms ≈ 2.9 nm at 500 °C) and a crystal size that is monotonously increasing from 8 to 32 nm for deposition temperatures in the range of 200-500 °C. The latter appears to have a direct impact on the field-effect electron mobility, which is found to increase with increasing ZnO crystal size. The maximum mobility and current on/off ratio is obtained from thin-film transistors fabricated using ZnO films deposited at >400 °C yielding values on the order of 25 cm 2 V-1s-1 and 106, respectively. The evolution of the structural and electronic properties of ZnO films grown by spray pyrolysis as a function of deposition temperature is reported. It is established that higher deposition temperatures lead to the formation of larger ZnO crystalline domains and the fabrication of n-channel thin-film transistors with significantly improved operating characteristics. © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Original languageEnglish (US)
Pages (from-to)525-531
Number of pages7
JournalAdvanced Functional Materials
Volume21
Issue number3
DOIs
StatePublished - Feb 8 2011
Externally publishedYes

Keywords

  • Solution Processing
  • Spray Pyrolysis
  • Thin-Film Transistors
  • Transparent Electronics
  • Zinc Oxide

ASJC Scopus subject areas

  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics

Fingerprint Dive into the research topics of 'Structural and electrical characterization of ZnO films grown by spray pyrolysis and their application in thin-film transistors'. Together they form a unique fingerprint.

Cite this