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Enhanced solar light absorption in inverse opals via higher-order photonic modes and angular tuning

Léo Weber* and Olivier Deparis

  • *Contact author: leo.weber@unamur.be
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Phys. Rev. A 113, 013506 – Published 2 January, 2026

DOI: https://doi.org/10.1103/57n3-j162

Abstract

Higher-order photonic modes have the potential to achieve superior absorption enhancement in inverse opal photocatalysts, beyond conventional blue or red edge slow light modes. This study reports a finite element method, numerical investigation of TiO2 inverse opals with an ultrathin material skeleton and varying diameters of interconnected pores, at different angle of incidence. Both diameter and angle variations are used to tune slow light modes to the TiO2 electronic band edge in the near-UV. In the case of air-filled pores, relevant to gas-phase photocatalysis, for a pore diameter of 240 nm, at normal incidence, the absorption enhancement factor reached a maximum value of α=2.07 thanks to tuning of the fifth allowed mode of the band structure. By contrast, for pore diameters corresponding to red (blue) edge tuning, an enhancement factor of only α=1.18 (α=1.97) could be achieved at normal incidence. Tighter confinement of the fifth mode into the skeleton is responsible for this enhanced performance. At 45∘ oblique incidence, tuning of that mode leads to even further enhancement (α=2.42) due to better coupling and light trapping caused by the nonzero in-plane component of the wave vector. In the case of water-filled pores, relevant to liquid-phase photocatalysis, for a pore diameter of 280 nm at normal incidence, the enhancement factor (α=2.39) greatly outperforms blue edge tuning (α=1.62) thanks to the tuning of the allowed modes from ninth to 15th of the band structure. We believe our study will offer additional insights into exploiting slow light effects in inverse opals for photocatalysis, and more generally, solar energy conversion applications.

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References (39)

  1. A. Fujishima and K. Honda, Electrochemical photolysis of water at a semiconductor electrode, Nature (London) 238, 37 (1972).
  2. M. Rafique, S. Hajra, M. Irshad, M. Usman, M. Imran, M. A. Assiri, and W. M. Ashraf, Hydrogen Production using TiO2-based photocatalysts: A comprehensive review, ACS Omega 8, 25640 (2023).
  3. S. Mishra and B. Sundaram, A review of the photocatalysis process used for wastewater treatment, Materials Today: Proc. 102, 393 (2024).
  4. F. He, W. Jeon, and W. Choi, Photocatalytic air purification mimicking the self-cleaning process of the atmosphere, Nat. Commun. 12, 2528 (2021).
  5. A. Chakravorty and S. Roy, A review of photocatalysis, basic principles, processes, and materials, Sustain. Chem. Environ. 8, 100155 (2024).
  6. M. K. Seery, R. George, P. Floris, and S. C. Pillai, Silver Doped titanium dioxide nanomaterials for enhanced visible light photocatalysis, J. Photochem. Photobiol. A: Chem. 189, 258 (2007).
  7. A. Balapure, J. R. Dutta, and R. Ganesan, Recent advances in semiconductor heterojunctions: A detailed review of the fundamentals of photocatalysis, charge transfer mechanism and materials, RSC Appl. Interfaces 1, 43 (2024).
  8. X. Chen, L. Liu, P. Yu, and S. S. Mao, Increasing solar absorption for photocatalysis with black hydrogenated Titanium dioxide nanocrystals, Science 331, 746 (2011).
  9. T. Wang, H.-J. Wang, J.-S. Lin, J.-L. Yang, F.-L. Zhang, X.-M. Lin, Y.-J. Zhang, S. Jin, and J.-F. Li, Plasmonic photocatalysis: Mechanism, applications, and perspectives, Chin. J. Struct. Chem. 42, 100066 (2023).
  10. A. Amirjani, N. B. Amlashi, and Z. S. Ahmadiani, Plasmon-enhanced photocatalysis based on plasmonic nanoparticles for energy and environmental solutions: A review, ACS Appl. Nano Mater. 6, 9085 (2023).
  11. J. Zhang, X. Cai, X. Fu, D. Teng, G. Murtaza, Z. Meng, Z. Jia, and L. Qiu, Slow light effect enhances the photocatalytic effect of inverse opal TiO2-based photonic nanocrystals, ACS Appl. Nano Mater. 7, 15376 (2024).
  12. E. Eftekhari, P. Broisson, N. Aravindakshan, Z. Wu, I. S. Cole, X. Li, D. Zhao, and Q. Li, Sandwich-structured TiO2 inverse opal circulates slow photons for tremendous improvement in solar energy conversion efficiency, J. Mater. Chem. A 5, 12803 (2017).
  13. H. Xiang, S. Yang, E. Talukder, C. Huang, and K. Chen, Research and application progress of inverse opal photonic crystals in photocatalysis, Inorganics 11, 337 (2023).
  14. M. Wu, J. Jin, J. Liu, Z. Deng, Y. Li, O. Deparis, and B.-L. Su, High photocatalytic activity enhancement of Titania inverse opal films by slow photon effect induced strong light absorption, J. Mater. Chem. A 1, 15491 (2013).
  15. V. Likodimos, Photonic crystal-assisted visible light activated TiO2 photocatalysis, Appl. Catal. B: Environ. 230, 269 (2018).
  16. M. Curti, J. Schneider, D. W. Bahnemann, and C. B. Mendive, Inverse opal photonic crystals as a strategy to improve photocatalysis: Underexplored questions, J. Phys. Chem. Lett. 6, 3903 (2015).
  17. X. Zhang and S. John, Enhanced photocatalysis by light-trapping optimization in inverse opals, J. Mater. Chem. A 8, 18974 (2020).
  18. X. Zhang and S. John, Photonic crystal light trapping for photocatalysis, Opt. Express 29, 22376 (2021).
  19. P. Birnal, Films minces micro/nanostructurés: Synthèse par ALD de composites associant opales inverses de TiO2 et nanoparticules d'or pour des applications photocatalytiques, Ph.D. thesis, Université Bourgogne Franche-Comté, France, 2021.
  20. D. Gaillot, T. Yamashita, and C. J. Summers, Photonic band gaps in highly conformal inverse-opal based photonic crystals, Phys. Rev. B 72, 205109 (2005).
  21. O. Deparis, S. R. Mouchet, and B. Su, Light harvesting in photonic crystals revisited: Why do slow photons at the blue edge enhance absorption? Phys. Chem. Chem. Phys. 17, 30525 (2015).
  22. E. Armstrong and C. O'Dwyer, Artificial opal photonic crystals and inverse opal structures: Fundamentals and applications from optics to energy storage, J. Mater. Chem. C 3, 6109 (2015).
  23. O. Habli, T. L. Madanu, B.-L. Su, and O. Deparis, Computational analysis of solar light harvesting properties of TiO2−BiVO4 inverse opals for applications in photocatalysis, J. Energy. Chem. 113, 610 (2025).
  24. T. L. Madanu, L. Chaabane, S. R. Mouchet, O. Deparis, and B.-L. Su, Manipulating multi-spectral slow photons in bilayer inverse opal TiO2@BiVO4 composites for highly enhanced visible light photocatalysis, J. Colloid Interface Sci. 647, 233 (2023).
  25. M. N. Polyanskiy, Refractiveindex. Info database of optical constants, Scientific Data 11, 94 (2024).
  26. T. Siefke, S. Kroker, K. Pfeiffer, O. Puffky, K. Dietrich, D. Franta, I. Ohlídal, A. Szeghalmi, E.-B. Kley, and A. Tünnermann, Materials pushing the application limits of wire grid polarizers further into the deep ultraviolet spectral range, Adv. Opt. Mater. 4, 1780 (2016).
  27. R. W. Clough, The finite element method in plane stress analysis, in Proceedings of the 2nd ASCE Conference on Electronic Computation (American Society of Civil Engineers, Reston, VA, 1960), pp. 345–378.
  28. comsol multiphysics® v. 6.3, https://www.comsol.com (2023), COMSOL AB.
  29. H. Tang, F. Du, S. Carr et al., Modeling the optical properties of twisted bilayer photonic crystals, Light: Sci. Appl. 10, 157 (2021).
  30. J. D. Joannopoulos, S. G. Johnson, J. N. Winn, and R. D. Meade, Photonic Crystals: Molding the Fllow of Light, 2nd ed. (Princeton University Press, Princeton, NJ, 2008).
  31. L. Weber and O. Deparis, Numerical predictions of the improvement of solar energy harvesting in inverse opal photonic crystals by tuning the slow-light effect to higher photonic bands, in Photonic Fiber and Crystal Devices: Advances in Materials and Innovations in Device Applications XIX, Proceedings of SPIE, Vol. 13608, edited by S. Yin and R. Guo (SPIE, Bellingham, WA, 2025), p. 1360807.
  32. A. Mekawy, 3d photonic crystal (FCC, Opal, Hexagonal) using comsol - part 1, https://www.youtube.com/watch?v=vf4cYA51DSo (2020).
  33. The internal quantum efficiency η is assumed to be equal to unity in this study, as the focus is placed on the structural effects governing absorption. In practice, TiO2 exhibits η<1 since photogenerated electron-hole pairs may recombine before participating in photocatalytic processes [39]. This assumption does not affect the validity of the conclusions from this work because taking η<1 would uniformly scale down the photon flux without altering the relative comparisons.
  34. National Renewable Energy Laboratory (NREL), Reference air mass 1.5 spectra, https://www2.nrel.gov/grid/solar-resource/spectra-am1.5.
  35. E. Pavarini, L. C. Andreani, C. Soci, M. Galli, F. Marabelli, and D. Comoretto, Band structure and optical properties of opal photonic crystals, Phys. Rev. B 72, 045102 (2005).
  36. M. Curti, G. Zvitco, M. A. Grela, and C. B. Mendive, Angle dependence in slow photon photocatalysis using TiO2 inverse opals, Chem. Phys. 502, 33 (2018).
  37. T. L. Madanu, S. R. Mouchet, O. Deparis, J. Liu, Y. Li, and B.-L. Su, Tuning and transferring slow photons from TiO2 photonic crystals to BiVO4 nanoparticles for unprecedented visible light photocatalysis, J. Colloid Interface Sci. 634, 290 (2023).
  38. S. G. Tikhodeev, A. L. Yablonskii, E. A. Muljarov, N. A. Gippius, and T. Ishihara, Quasiguided modes and optical properties of photonic crystal slabs, Phys. Rev. B 66, 045102 (2002).
  39. A. Kudo and Y. Miseki, Heterogeneous photocatalyst materials for water splitting, Chem. Soc. Rev. 38, 253 (2009).

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Phys. Rev. A 113, 013506– Published 2 January, 2026
  • Received 20 October 2025
  • Accepted 4 December 2025
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Published by the American Physical Society under the terms of the Creative Commons Attribution 4.0 International license. Further distribution of this work must maintain attribution to the author(s) and the published article's title, journal citation, and DOI.

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