arXiv:2601.17161v1 Announce Type: new
Abstract: The Deep Underground Neutrino Experiment (DUNE) Phase-II Far Detector is considering an unprecedentedly large-area ~2000 m$^2$ photon detection system to achieve a target mean light yield of 180 PE/MeV. Meeting this requirement demands scalable, cost-effective, and high-quality wavelength-shifter (WLS) coatings capable of converting 127 nm liquid-argon scintillation light into visible photons with high efficiency. We report on the successful realization of an industrial physical vapor deposition (PVD) process for textit{p}-terphenyl (pTP) coatings, adapted from vacuum deposition techniques developed for OLED display manufacturing, to produce uniform WLS layers on large-area inorganic substrates, a task traditionally challenged by adhesion and uniformity issues at organic–inorganic interfaces. Surface characterization by profilometry and spectroscopic measurements confirms sub-10% thickness uniformity for 1-2 $mu$m films and emission spectra consistent with high-quality pTP reference samples. The industrial process demonstrates reproducibility, scalability, and significantly reduced production time compared to laboratory-based methods, while maintaining the optical quality required for large-scale liquid-argon time-projection chamber (LArTPC) photon detection systems. These results establish a viable pathway for mass production of high-performance pTP coatings for DUNE FD3 and future neutrino experiments.