Epitaxial Self‐Assembled Vertically Aligned Nanocomposite Photoelectrodes with Tunable Ambipolar Response

Journal article

Ron Fishov, Alexander Rashkovskiy, Vladimir Ezerski, D. Grave
Advanced Optical Materials, 2025

Cite

APA Click to copy
Fishov, R., Rashkovskiy, A., Ezerski, V., & Grave, D. (2025). Epitaxial Self‐Assembled Vertically Aligned Nanocomposite Photoelectrodes with Tunable Ambipolar Response. Advanced Optical Materials.

Chicago/Turabian Click to copy
Fishov, Ron, Alexander Rashkovskiy, Vladimir Ezerski, and D. Grave. “Epitaxial Self‐Assembled Vertically Aligned Nanocomposite Photoelectrodes with Tunable Ambipolar Response.” Advanced Optical Materials (2025).

MLA Click to copy
Fishov, Ron, et al. “Epitaxial Self‐Assembled Vertically Aligned Nanocomposite Photoelectrodes with Tunable Ambipolar Response.” Advanced Optical Materials, 2025.

BibTeX Click to copy

@article{ron2025a,
  title = {Epitaxial Self‐Assembled Vertically Aligned Nanocomposite Photoelectrodes with Tunable Ambipolar Response},
  year = {2025},
  journal = {Advanced Optical Materials},
  author = {Fishov, Ron and Rashkovskiy, Alexander and Ezerski, Vladimir and Grave, D.}
}

Abstract

Photocurrent polarity switching in semiconductor photoelectrodes enables the development of optoelectronic switches and logic devices driven by illumination and applied potential. Here, a new class of ambipolar photoelectrodes that display controlled photoelectrochemical photocurrent switching (PEPS) behavior, based on epitaxial self‐assembled vertically aligned NiTiO3–TiO2 nanocomposite thin films synthesized via pulsed laser deposition (PLD) is reported. Phase‐pure NiTiO3 and TiO2 films are grown under optimized deposition conditions, while mixed‐phase nanocomposites are engineered by adjusting the Ni/Ti ratio of the ablated targets. Structural characterization confirms the formation of vertically aligned epitaxial rutile TiO2 nanocolumns within the NiTiO3 matrix at high Ni/Ti ratios, and NiTiO3 nanocolumns within the TiO2 matrix at low Ni/Ti ratios. Photoelectrochemical (PEC) measurements reveal ambipolar behavior with a composition‐dependent crossover potential between anodic and cathodic photocurrents tunable over a range of 800 mV. Phase‐pure NiTiO3 exhibits intrinsic photocurrent switching, whereas TiO2 maintains a stable photoanodic response. The introduction of NiTiO3 into TiO2 substantially disrupts photoanodic performance, while TiO2 incorporation into NiTiO3 enhances photoanodic photocurrent without significantly affecting photocathodic activity. These findings establish vertically aligned nanocomposites (VANs) as a new platform for switchable photoelectrodes and provide new insights into the role of mixed‐phase oxide structures in PEC logic devices and optoelectronic switching applications.