A simple, low-cost, and nontoxic aqueous ink chemistry is described for digital printing of ZnO films. Selective design through controlled precipitation, purification, and dissolution affords an aqueous Zn(OH)(x)(NH(3))(y)((2-x)+) solution that is stable in storage, yet promptly decomposes at temperatures below 150 degrees C to form wurtzite ZnO. Dense, high-quality, polycrystalline ZnO films are deposited by ink-jet printing and spin-coating, and film structure is elucidated via X-ray diffraction and electron microscopy. Semiconductor film functionality and quality are examined through integration in bottom-gate thin-film transistors. Enhancement-mode TFTs with ink-jet printed ZnO channels annealed at 300 degrees C are found to exhibit strong field effect and excellent current saturation in tandem with incremental mobilities from 4-6 cm(2) V(-1) s(-1). Spin-coated ZnO semiconductors processed at 150 degrees C are integrated with solution-deposited aluminum oxide phosphate dielectrics in functional transistors, demonstrating both high performance, i.e., mobilities up to 1.8 cm(2) V(-1) s(-1), and the potential for low-temperature solution processing of all-oxide electronics.

Aluminum oxide phosphate thin films have been deposited via spin coating from aqueous solution and utilized as gate dielectrics in thin-film transistors. Films are atomically smooth, dense, and amorphous, while exhibiting excellent morphological stability to 1000 °C. Film chemistry and structure are investigated by using an array of analytical techniques including X-ray diffraction, FT-IR spectroscopy, and electronmicroprobe analysis. Dielectric film functionality and quality are explored through integration in capacitor and thin-film transistor devices. Film permittivity for an Al 2 PO 5.5 composition is found to be 4.8 in combination with leakage current densities <10 nA cm -2 at 1 MV cm -1 and current-limited breakdown fields up to 10 MV cm -1 . Thin-film transistors fabricated with these oxide phosphate dielectrics and sputtered ZnO channels exhibit strong field-effect and current saturation with incremental mobilities up to 3.5 cm 2 V -1 s -1 . The ability of the amorphous matrix to accommodate additional oxide components is demonstrated by the incorporation of La 2 O 3 and a resulting increase in film permittivity to 8.5, while maintaining breakdown fields >4 MV cm -1 .

New thin‐film dielectrics and nanolaminates have been synthesized via aqueous‐solution deposition of Hf and Zr sulfates, where facile gelation and vitrification of the precursor solution have been achieved without organic additives. X‐ray reflectivity, imaging, and metal‐insulator‐metal capacitor performance reveal that smooth, atomically dense films are readily produced by spin coating and modest thermal treatment (T < 325 °C). Dielectric characteristics include permittivities covering the range of 9–12 with breakdown fields up to 6 MV cm–1. Performance as gate dielectrics is demonstrated in field‐effect transistors exhibiting small gate‐leakage currents and qualitatively ideal device performance. The low‐temperature processing, uniformity, and pore‐free nature of the films have also allowed construction of unique, high‐resolution nanolaminates exhibiting individual layers as thin as 3 nm.

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