A diverse array of semiconductor-based composite materials have been prepared, characterized, and utilized in many applications ranging from photocatalysis, photovoltaic cells, photoelectrochromic displays, and light-emitting devices to sensors. The composite architectures (nanoarchitectures in many cases) are equally diverse. In this review, we highlight the advances that have been made and identify some of the gaps in our current knowledge of these materials. Size quantization effects and semiconductor quantum dots are also discussed.

https://www.uta.edu/cos/raj/pub/Chem.Mater.Review-1.pdf

Semiconductor-Based Composite Materials: Preparation, Properties, and Performance

Nucleation and growth in TiO2 films prepared by sputtering and evaporation

Growth of titanium dioxide thin films by atomic layer epitaxy

Uniform TiO2 thin films with a large er (up to 86) were prepared at low temperatures (200-400°C) by CVD. The films deposited at 200°C were amorphous and those at high temperatures were polycrystalline structures of anatase. The electronic properties of a TiO2/Si interface were analyzed in detail using metal-insulator-semiconductor structures. The minimum interface state density in the bandgap was as low as 2×1011 cm-2 eV-1, showing the usefulness of the TiO2 films for the gate insulators of MIS diodes. An anomalous behavior of photo-induced current observed for the first time is also presented.

https://iopscience.iop.org/article/10.1143/JJAP.25.1288/pdf

Electronic Properties of the Interface between Si and TiO2 Deposited at Very Low Temperatures

Single-material TiO2 double-layer antireflection coatings

Thin film was produced at 150°C by chemical vapor deposition using hydrolysis of tetraisopropyl titanate. Films were amorphous as grown, but annealing in air caused crystallization, with anatase formed beginning at 350°C and rutile at 700°C. Density and index of refraction increased substantially with increasing anneal temperature, while etch susceptibility in and decreased. Comparison with literature data showed two groups of processes. One group yields films having properties that gradually approach those of rutile with increasing process temperature. The other group gives rutile directly at moderate temperatures. Deposition of amorphous film, followed by etching and annealing is suggested as a means for pattern definition.

TiO2 Film Properties as a Function of Processing Temperature

Thin film TiO2 was produced at 150 C by chemical vapor deposition using hydrolysis of tetraisopropyl titanate. Films were amorphous as grown, but annealing in air caused crystallization, with anatase formed beginning at 350 C and rutile at 700 C. Density and index of refraction increased substantially with increasing anneal temperature, while etch susceptibility in HF and H2SO4 decreased. Comparison with literature data showed two groups of processes. One group yields films having properties that gradually approach those of rutile with increasing process temperature. The other group gives rutile directly at moderate temperatures. Deposition of amorphous film followed by etching and annealing is suggested as a means for pattern definition.

https://ntrs.nasa.gov/api/citations/19730009053/downloads/19730009053.pdf

K. J. Sladek

Papers

TiO2 Film Properties as a Function of Processing Temperature

TiO2 film properties as a function of processing temperature, volume 3

Eigenschaften von tio2-filmen in abhaengigkeit von der bearbeitungstemperatur