Low-temperature growth of InO films was demonstrated at 70-250 °C by plasma-enhanced atomic layer deposition (PEALD) using a newly synthesized liquid indium precursor, dimethyl(N-ethoxy-2,2-dimethylcarboxylicpropanamide)indium (MeIn(EDPA)), and O plasma for application to high-mobility thin film transistors. Self-limiting InO PEALD growth was observed with a saturated growth rate of approximately 0.053 nm/cycle in an ALD temperature window of 90-180 °C. As-deposited InO films showed negligible residual impurity, film densities as high as 6.64-7.16 g/cm, smooth surface morphology with a root-mean-square (RMS) roughness of approximately 0.2 nm, and semiconducting level carrier concentrations of 10-10 cm. Ultrathin InO channel-based thin film transistors (TFTs) were fabricated in a coplanar bottom gate structure, and their electrical performances were evaluated. Because of the excellent quality of InO films, superior electronic switching performances were achieved with high field effect mobilities of 28-30 and 16-19 cm/V·s in the linear and saturation regimes, respectively. Furthermore, the fabricated TFTs showed excellent gate control characteristics in terms of subthreshold swing, hysteresis, and on/off current ratio. The low-temperature PEALD process for high-quality InO films using the developed novel In precursor can be widely used in a variety of applications such as microelectronics, displays, energy devices, and sensors, especially at temperatures compatible with organic substrates.

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In semitransparent perovskite solar cells with n–i–p configuration, thermal evaporation is the common method to deposit the sputter buffer material, such as molybdenum oxide and tungsten oxide. Buffer layers are especially necessary when using organic hole transporting layers, as they are more susceptible to get damaged when sputtering the top transparent conducting oxide. However, there is a limited selection of possible materials and limited control of the materials properties by thermal evaporation, which leads to inefficient protection against sputtering and poor air stability. While there have been well‐established buffer layers by atomic layer deposition, including tin oxide, for p–i–n structured semitransparent perovskite solar cells, this is not the case for n–i–p structured devices. Here, copper oxide is demonstrated by pulsed‐chemical vapor deposition incorporated into perovskite solar cells for the sputter buffer layer, which result in stable encapsulated semitransparent devices maintaining over 95% of the maximum efficiency under AM 1.5 G at maximum power point tracking for 150 h without any temperature control.