Doped Titanium Dioxide Thin Films for Energy Applications

Titanium dioxide (TiO₂) thin films doped with aliovalent or isovalent elements have emerged as versatile components in energy conversion and storage technologies. By introducing controlled impurities such as niobium, nitrogen or tantalum into the TiO₂ lattice, researchers tailor the electronic band structure, charge‐carrier density and surface chemistry to suit specific applications. Doping strategies aim to extend light absorption into the visible region, enhance electrical conductivity and optimise interfacial charge transfer. Such modifications underpin advances in photocatalysis, transparent conducting oxides (TCOs), photocatalytic water splitting and next‐generation solar cells. Deployment of doped TiO₂ thin films on glass, fluorine‐doped tin oxide or metal substrates has demonstrated improvements in photoconversion efficiency, pseudocapacitive energy storage and charge transport. The development of scalable deposition methods—such as atomic layer deposition, sputtering, sol–gel and mechanochemical synthesis—facilitates integration into photovoltaic, photoelectrochemical and electrochemical devices. Globally, these films offer an Earth‐abundant, low‐cost route to sustainable energy solutions, supporting decentralised power generation and efficient energy storage systems.

Research from Nature Portfolio

Recent studies have elucidated the role of nanoscale interlayers and compositional gradients in doped TiO₂ films. Sequential deposition of oxygen‐rich seed layers followed by oxygen‐poor bulk layers has been shown to suppress detrimental polymorphic phases, yielding films with exceptionally low resistivity and high transparency on glass substrates. This bilayer approach offers precise control of crystallisation and carrier mobility without breaking vacuum between steps. In parallel, mechanically induced Nb incorporation into TiO₂ has produced metastable particles that, after thermal treatment, spontaneously form core–shell compositional heterojunctions. These gradient structures markedly enhance photocatalytic activity under both ultraviolet and visible illumination by promoting spatial charge separation and reducing recombination losses. Together, these findings demonstrate that nanoscale chemical architecture and processing‐induced compositional gradients are powerful levers to engineer doped TiO₂ films for energy‐conversion applications.

Doped Titanium Dioxide Thin Films for Energy Applications publication trend

The graph below shows the total number of articles in doped titanium dioxide thin films for energy applications across all publications each year (not limited to Nature Index journals).

Technical terms

Doping: Introduction of impurity atoms into a semiconductor to modify its electronic properties.

Thin film: A layer of material ranging from a few nanometres to several micrometres in thickness, deposited on a substrate.

Anatase: A tetragonal polymorph of TiO₂ known for high photocatalytic activity and favourable charge transport.

Photocatalysis: Acceleration of a chemical reaction by light‐induced generation of charge carriers in a semiconductor.

Band gap: The energy difference between the valence and conduction bands in a semiconductor, determining light absorption edge.

Transparent conducting oxide (TCO): A semiconductor that combines optical transparency with electrical conductivity, used as electrode in optoelectronic devices.

Pseudocapacitance: Charge storage mechanism involving fast, reversible redox reactions at or near the electrode surface.

Heterojunction: Interface between two materials with differing band structures, facilitating directional charge separation.

References

1. Mesoporous niobium-doped titanium dioxide films from the assembly of crystalline nanoparticles: study on the relationship between the band structure, conductivity and charge storage mechanism. Journal of Materials Chemistry A (2017).
2. Study of nitrogen ion doping of titanium dioxide films. Applied Surface Science (2018).
3. Tantalum-Doped TiO2 Prepared by Atomic Layer Deposition and Its Application in Perovskite Solar Cells. Nanomaterials (2021).
4. The Role of Nanoscale Seed Layers on the Enhanced Performance of Niobium doped TiO2 Thin Films on Glass. Scientific Reports (2016).
5. Spontaneously formed gradient chemical compositional structures of niobium doped titanium dioxide nanoparticles enhance ultraviolet- and visible-light photocatalytic performance. Scientific Reports (2021).