原子层沉积
材料科学
结晶度
钼
薄膜
氢
无定形固体
氧化物
化学工程
化学计量学
纳米技术
分析化学(期刊)
复合材料
冶金
结晶学
化学
物理化学
有机化学
工程类
作者
Jan-Lucas Wree,Detlef Rogalla,Andreas Ostendorf,K.D. Schierbaum,Anjana Devi
标识
DOI:10.1021/acsami.2c19827
摘要
Molybdenum oxide thin films are very appealing for gas sensing applications due to their tunable material characteristics. Particularly, the growing demand for developing hydrogen sensors has triggered the exploration of functional materials such as molybdenum oxides (MoOx). Strategies to enhance the performance of MoOx-based gas sensors include nanostructured growth accompanied by precise control of composition and crystallinity. These features can be delivered by using atomic layer deposition (ALD) processing of thin films, where precursor chemistry plays an important role. Herein, we report a new plasma-enhanced ALD process for molybdenum oxide employing the molybdenum precursor [Mo(NtBu)2(tBu2DAD)] (DAD = diazadienyl) and oxygen plasma. Analysis of the film thickness reveals typical ALD characteristics such as linearity and surface saturation with a growth rate of 0.75 Å/cycle in a broad temperature window between 100 and 240 °C. While the films are amorphous at 100 °C, crystalline β-MoO3 is obtained at 240 °C. Compositional analysis reveals nearly stoichiometric and pure MoO3 films with oxygen vacancies present at the surface. Subsequently, hydrogen gas sensitivity of the molybdenum oxide thin films is demonstrated in a laboratory-scale chemiresistive hydrogen sensor setup at an operation temperature of 120 °C. Sensitivities of up to 18% are achieved for the film deposited at 240 °C, showing a strong correlation between crystallinity, oxygen vacancies at the surface, and hydrogen gas sensitivity.
科研通智能强力驱动
Strongly Powered by AbleSci AI