TiO2の原子層沈殿の分析 表面化学と表面強化ラーマン光譜を用いたプロペンのオリゴメリゼーションの証拠
Ryan A Hackler1, Gyeongwon Kang1, George C Schatz1
1Department of Chemistry and Center for Catalysis and Surface Science , Northwestern University , Evanston , Illinois 60208 , United States.
Journal of the American Chemical Society
|December 13, 2018
まとめ
二酸化チタン (TiO2) の原子層堆積 (ALD) は,予期せぬ形で化学蒸気堆積 (CVD) の成長に移行することがあります. これは,前駆体副産物を含む副作用によるもので,表面蓄積と成長メカニズムの変化につながります.
科学分野:
- 材料科学
- 表面化学
- ナノテクノロジー
背景:
- 原子層堆積 (ALD) は薄膜堆積技術である.
- 二酸化チタン (TiO2) は様々な用途で広く使用されている材料です.
- ALDの成長メカニズムを理解することは,フィルムの性質を制御するために不可欠です.
研究 の 目的:
- チタンテトライソプロ酸化物 (TTIP) を使用してTiO2 ALDの初期サイクル中の表面化学を調査する.
- 暫定的な表面種と反応経路を特定する.
- ALDからCVDの成長への移行を理解する.
主な方法:
- 地表の種を監視するために,地表強化ラーマン光譜 (SERS) です.
- TTIP先駆体を使用したTiO2の原子層沈殿 (ALD)
- 機械的な洞察のための密度関数理論 (DFT) の計算.
主要な成果:
- 最初のALDサイクルは,無傷のイソプロオキシドリガンドとの典型的なリガンド交換を示した.
- その後のサイクルは異プロオキシドリガンドを検出できず,化学的性質が異なっていた.
- 孤立したTiO2サイトはイソプロピールアルコールの脱水を促進し,プロペンの形成とオリゴメリゼーション/ポリメリゼーションにつながった.
結論:
- TTIPの前身は,脱水とポリメリゼーション反応によるTiO2 ALDのCVDのような増加につながる可能性があります.
- 表面に結合したTiO2サイトは,これらの副作用において重要な役割を果たします.
- ALDプロセスは,副産物が新しく形成された表面部位と相互作用すると,CVDに進化することができます.
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