ACS Appl Mater Interfaces. 2018 Aug 1;10(30):25536-25546. doi: 10.1021/acsami.8b09482. Epub 2018 Jul 19.
A monolayer CaNbO (CNO) nanosheet was deposited on a Pt/Ti/SiO/Si substrate using the Langmuir-Blodgett method. This monolayer CNO nanosheet with a (001) surface termination was used as a seed layer to reduce the growth temperature of the crystalline (NaK )NbO (NKN) film. The crystalline NKN film was preferentially grown along the [001] direction at 400 °C. The ferroelectric and piezoelectric properties of this NKN film were influenced by the postannealing atmosphere due to the variations in the amounts of oxygen vacancies in the NKN film. The crystalline NKN film annealed at 300 °C under 50 Torr O atmosphere showed promising ferroelectric and piezoelectric properties; ε of 303 and tan δ of 2.0% at 100 kHz, P of 15.3 μC/cm, P of 11.7 μC/cm, and E of 78 kV/cm, and d of 139 pm/V. This NKN film showed the lowest leakage current, which can be explained by the Schottky emission mechanism. The Schottky barrier heights of the Pt/NKN and NKN/CNO/Pt interfaces were calculated to be 0.97 and 0.28 eV, respectively. The results of this work suggest a new method to grow crystalline thin films at low temperatures by using metal-oxide nanosheets as the seed layer.
采用 Langmuir-Blodgett 方法在 Pt/Ti/SiO/Si 基底上沉积了一层单层 CaNbO（CNO）纳米片。这种具有（001）表面终止的单层 CNO 纳米片可用作晶态（NaK）NbO（NKN）薄膜的籽晶层，以降低其生长温度。在 400°C 下，该晶态 NKN 薄膜优先沿[001]方向生长。由于 NKN 薄膜中氧空位数量的变化，该 NKN 薄膜的铁电和压电性能受后退火气氛的影响。在 50 Torr O 气氛下于 300°C 退火的晶态 NKN 薄膜表现出良好的铁电和压电性能，在 100 kHz 下ε为 303，tan δ为 2.0%，P 为 15.3 μC/cm，P 为 11.7 μC/cm，E 为 78 kV/cm，d 为 139 pm/V。该 NKN 薄膜表现出最低的漏电流，这可以用肖特基发射机制来解释。Pt/NKN 和 NKN/CNO/Pt 界面的肖特基势垒高度分别计算为 0.97 和 0.28 eV。这项工作的结果表明，通过使用金属氧化物纳米片作为籽晶层，在低温下生长晶态薄膜的新方法。
