Guillén Cecilia
Centro de Investigaciones Energéticas Medioambientales y Tecnológicas (CIEMAT), Avenida Complutense 40, 28040 Madrid, Spain.
Materials (Basel). 2025 May 18;18(10):2346. doi: 10.3390/ma18102346.
TiO is an abundant material on Earth, essential for the sustainable and cost-effective development of various technologies, with anatase being the most effective polymorph for photocatalytic and photovoltaic applications. Bulk crystalline anatase TiO exhibits a band gap energy E = 3.2 eV, for tetragonal lattice parameters a = 0.3785 nm and c = 0.9514 nm, but these characteristics vary for amorphous or polycrystalline thin films. Reactive magnetron sputtering has proven suitable for the preparation of TiO coatings on glass fiber substrates, with structural and optical characteristics that change during growth. Below a minimum thickness (t < 0.2 μm), the films have an amorphous nature or extremely small crystallite sizes not observable by X-ray diffraction. Afterwards, compressed quasi-randomly orientated crystallites are detected (volume strain ΔV = -0.02 and stress σ = -3.5 GPa for t = 0.2 μm) that evolve into relaxed and preferentially (004) orientated crystallites, reaching the standard anatase values at t ~ 1.4 μm with σ = 0.0 GPa. The band gap energy increases with lattice distortion according to the relation ∆E (eV) = -6∆V, and a further increase is observed for the thinnest coatings (∆E = 0.24 eV for t = 0.05 μm).
二氧化钛是地球上储量丰富的一种材料，对各种技术的可持续且具成本效益的发展至关重要，其中锐钛矿是光催化和光伏应用中最有效的多晶型物。块状晶体锐钛矿型二氧化钛的带隙能量E = 3.2电子伏特，其四方晶格参数a = 0.3785纳米，c = 0.9514纳米，但对于非晶或多晶薄膜，这些特性会有所不同。反应磁控溅射已被证明适用于在玻璃纤维基板上制备二氧化钛涂层，其结构和光学特性在生长过程中会发生变化。在最小厚度以下（t < 0.2微米），薄膜具有非晶性质或微晶尺寸极小，无法通过X射线衍射观察到。之后，检测到压缩的准随机取向微晶（对于t = 0.2微米，体积应变ΔV = -0.02且应力σ = -3.5吉帕斯卡），这些微晶会演变成松弛的且优先（004）取向的微晶，在t ~ 1.4微米时达到标准锐钛矿值，此时σ = 0.0吉帕斯卡。带隙能量根据∆E（电子伏特）= -6∆V的关系随晶格畸变而增加，对于最薄的涂层还观察到进一步增加（对于t = 0.05微米，∆E = 0.24电子伏特）。
