Precursor-route ZnO films from a mixed casting solvent for high performance aqueous electrolyte-gated transistors

• Published in: Physical chemistry chemical physics : PCCP 2015-01, Vol.17 (46), p.31247-31252
• Main Authors: Althagafi, Talal M, Algarni, Saud A, Al Naim, Abdullah, Mazher, Javed, Grell, Martin
• Format: Article
• Language: English
• Subjects: Acetone; Ethyl alcohol; Phosphates; Precursors; Semiconductor devices; Solvents; Thin film transistors; Zinc oxide
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/c5cp03326h

We significantly improved the performance of precursor-route semiconducting zinc oxide (ZnO) films in electrolyte-gated thin film transistors (TFTs). We find that the organic precursor to ZnO, zinc acetate (ZnAc), dissolves more readily in a 1 : 1 mixture of ethanol (EtOH) and acetone than in pure EtOH, pure acetone, or pure isopropanol. XPS and SEM characterisation show improved morphology of ZnO films converted from a mixed solvent cast ZnAc precursor compared to the EtOH cast precursor. When gated with a biocompatible electrolyte, phosphate buffered saline (PBS), ZnO thin film transistors (TFTs) derived from mixed solvent cast ZnAc give 4 times larger field effect current than similar films derived from ZnAc cast from pure EtOH. The sheet resistance at V G = V D = 1 V is 30 kΩ −1 , lower than for any organic TFT, and lower than for any electrolyte-gated ZnO TFT reported to date. We significantly improved the performance of precursor-route semiconducting zinc oxide (ZnO) films in electrolyte-gated thin film transistors (TFTs).