Transparent thin-film transistors (TTFTs) with an amorphous zinc tin oxide channel layer formed via rf magnetron sputter deposition are demonstrated. Field-effect mobilities of 5-15 and 20-50 cm 2 V −1 s −1 are obtained for devices post-deposition annealed at 300 and 600°C, respectively. TTFTs processed at 300 and 600°C yield devices with turn-on voltage of 0-15 and −5-5 V, respectively. Under both processing conditions, a drain current onto off ratio greater than 10 7 is obtained. Zinc tin oxide is one example of a new class of high performance TTFT channel materials involving amorphous oxides composed of heavy-metal cations with ͑n −1͒d 10 ns 0 ͑n ജ 4͒ electronic configurations.

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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.

High mobility, n-type transparent thin-film transistors ͑TTFTs͒ with a zinc indium oxide ͑ZIO͒ channel layer are reported. Such devices are highly transparent with ϳ85% optical transmission in the visible portion of the electromagnetic spectrum. ZIO TTFTs annealed at 600°C operate in depletion-mode with threshold voltages −20 to −10 V and turn-on voltages ϳ3 V less than the threshold voltage. These devices have excellent drain current saturation, peak incremental channel mobilities of 45-55 cm 2 V −1 s −1 , drain current onto off ratios of ϳ10 6 , and inverse subthreshold slopes of ϳ0.8 V / decade. In contrast, ZIO TTFTs annealed at 300°C typically operate in enhancement-mode with threshold voltages of 0-10 V and turn-on voltages 1-2 V less than the threshold voltage. These 300°C devices exhibit excellent drain-current saturation, peak incremental channel mobilities of 10-30 cm 2 V −1 s −1 , drain current onto off ratios of ϳ10 6 , and inverse subthreshold slopes of ϳ0.3 V / decade. ZIO TTFTs with the channel layer deposited near room temperature are also demonstrated. X-ray diffraction analysis indicates the channel layers of ZIO TTFTs to be amorphous for annealing temperatures up to 500°C and polycrystalline at 600°C. Low temperature processed ZIO is an example of a class of high performance TTFT channel materials involving amorphous oxides composed of heavy-metal cations with ͑n −1͒d 10 ns 0 ͑n ജ 4͒ electronic configurations.

Electrical and thermal transport properties of synthetic tetrahedrites Cu10TM2Sb4S13 (TM = Mn, Fe, Co, Ni, Zn) and the solid solution Cu12–x Mn x Sb4S13 (0 ≤ x ≤ 2) have been studied in the context of thermoelectric performance. Among these materials, the parent compound Cu12Sb4S13 exhibits the highest power factor, which is primarily derived from a high electrical conductivity. All substituted derivatives display a significant and uniform reduction in thermal conductivity. Within the TM series, the Mn-substituted sample displays the highest ZT (0.8 at 575 K). Changing the Mn concentration to Cu11MnSb4S13 produces the highest ZT, i.e., 1.13 at 575 K. The relatively high value derives from a favorable balance of low thermal conductivity and a relatively high power factor.