Search arXiv⌕ Search
Home/Archive/arXiv

arXiv · 2507.03008

On the Underlying Mechanism of Light-Induced Patterning of N719-Stained Photoanodes for "Photovoltaic Photographs"

Allyson Robert·Nico Fransaert·Willem Awouters·Wouter Marchal·Peter Adriaensens·Roland Valcke·Jean V. Manca
View original source ↗Read source document ↗Export metadata ↓

Abstract

Recently, "photovoltaic photographs" were proposed as a creative application of photovoltaic technologies, relevant in fields such as architecture or the automotive industry. In this application an image is created by light-induced patterning of the photoactive layer, causing a local change in the appearance of the solar cell. In order to further develop this concept, it is crucial to elucidate the mechanism underlying these local changes. Here, UV-VIS and infrared spectroscopic techniques, as well as Gas Chromatography - Mass Spectrometry and time-of-flight secondary ion mass spectrometry, have been used to investigate the physico-chemical changes induced by this process in the photoactive layer of proof-of-concept photo-patterned dye-sensitized solar cells. We show that, for N719 photovoltaic photographs, TiO2 plays a crucial role and that the dye undergoes a multi-step chemical degradation, related to its isothiocyanate ligand. These insights are of importance for a better understanding of the photo-induced degradation of N719, a more substantiated control of the light-induced patterning process, and to design appropriate light-induced patterning techniques for other classes of solar cells.

Explore related subjects

physics.chem-phcond-mat.mtrl-sciphysics.optics

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

Allyson Robert, Nico Fransaert, Willem Awouters, Wouter Marchal, Peter Adriaensens, Roland Valcke, Jean V. Manca. 2025-07-02. On the Underlying Mechanism of Light-Induced Patterning of N719-Stained Photoanodes for "Photovoltaic Photographs". https://doi.org/10.1016/j.solmat.2025.114113

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related papers

arXiv2026

SPIBER: Reconstructing Free Energy Landscapes from Short, Unconverged Trajectories with Generative Flow Networks

Molecular systems have many degrees of freedom, but their metastable behavior can often be described by a few collective variables. Identifying these variables and estimating free energies along them from limited simulation data remains a challenging, important problem. Separate short trajectories may sample different metastable states without capturing transitions or establishing their relative equilibrium populations. For unbiased trajectories generated with the same Hamiltonian at a single temperature, alternate methods based on histogram reweighting cannot correct this imbalance. Here we present SPIBER, which combines the State Predictive Information Bottleneck (SPIB) with Generative Flow Networks (GFlowNets). SPIB uses deep learning to approximate slow degrees of freedom through a past-future information bottleneck, retaining information needed to predict future metastable states. We show that this compression limits conditional entropy variations in populated regions, allowing conditional mean potential energies, which are much easier to calculate, to be used to approximate free energy differences. Given sufficient local sampling to estimate these energies, they define the target distribution for GFlowNets, energy-based generative samplers that sample according to estimated thermodynamic stability rather than observed populations. For a particle in a radial double-well potential, for alanine dipeptide, and for the nine-residue peptide AIB9, SPIBER recovers free energy differences between sampled metastable states to within one thermal energy unit of reference values. The method combines collective-variable learning and free energy estimation in up to four latent dimensions, without requiring converged state populations or additional molecular dynamics simulations.

physics.chem-ph↗
arXiv2026

Intrinsic Matching Frustration in Fluctuating Finite Systems

We formulate intrinsic matching frustration (IMF), a fluctuation-induced, kinetics-independent reduction in the mean capacity permitted by a prescribed matching rule. For complementary one-to-one matching, the instantaneous capacity is set by the minority population, so fluctuations produce a nonzero mean deficit even when the two populations are balanced on average. At finite size, this deficit depends on the full distribution of the population difference and is determined by its variance alone only in the Gaussian limit. Compartmentalization hides matching capacity by preventing cancellation between local imbalances of opposite sign. Fusion releases this hidden capacity monotonically under coarse graining, producing a measurable recovery of product yield following local reaction to completion.

physics.chem-ph↗
arXiv2026

Phonon chirality as an additive control of CISS: a symmetry-protected law

Chirality-induced spin selectivity (CISS) is usually associated with molecular handedness. The possible contribution of chiral phonons is less established. We study a helical tight-binding model in which local phonon angular momentum modulates spin-dependent nearest-neighbor hopping. Fewest-switches surface hopping calculations give the transmitted spin polarization $\mathrm{SP}=aC+b\mathrm{PH}$. Here $C$ is the molecular chirality and $\mathrm{PH}$ is the phonon chirality. A mirror symmetry reverses $C$, $\mathrm{PH}$, and $\mathrm{SP}$ simultaneously. This symmetry excludes both a chirality-independent offset and a $C\cdot\mathrm{PH}$ term. The phonon contribution can therefore enhance, cancel, or reverse the molecular CISS signal.

physics.chem-ph↗