Nonlinear optical and optical limiting properties of In2S3 chalcogenide thin films: Influence of defect states and deposition technique


Hilal O., Emur H. G., Dogan A., YILDIZ E., Isik M., PARLAK M., ...Daha Fazla

Journal of Luminescence, cilt.293, 2026 (SCI-Expanded, Scopus) identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 293
  • Basım Tarihi: 2026
  • Doi Numarası: 10.1016/j.jlumin.2026.121804
  • Dergi Adı: Journal of Luminescence
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex, INSPEC
  • Anahtar Kelimeler: In2S3 thin films, Nonlinear absorption, Open-aperture Z-scan, Optical limiting, Two photon absorption
  • Ankara Üniversitesi Adresli: Evet

Özet

In this study, the nonlinear absorption (NA) and optical limiting (OL) properties of indium sulfide (In2S3) thin films prepared by physical vapor deposition (PVD) and radio-frequency (RF) magnetron sputtering were investigated. Linear optical analysis revealed distinct Urbach energies of 1.14 eV and 0.27 eV for the PVD-grown and RF-sputtered films, respectively, indicating higher defect density in the former. Photoluminescence (PL) measurements showed broader and stronger visible emission for the RF-sputtered film, while the PVD-grown film exhibited narrower near-band-edge emission. Femtosecond transient absorption spectroscopy further revealed that the PVD-grown film featured broad excited-state absorption and faster decay dynamics, whereas the RF-sputtered film displayed ground-state bleaching and longer lifetimes, consistent with fewer traps and reduced carrier loss. Open-aperture Z-scan analysis under 532 nm, 4 ns excitation indicated intensity-dependent NA dominated by defect-assisted processes. The effective nonlinear coefficients from the defect-saturation model were over an order of magnitude higher than those from the Sheik–Bahae model. The RF-sputtered film exhibited shallower defect states that enhanced sequential two-photon and free-carrier absorption, while the PVD-grown film showed early saturation due to localized-state filling. Optical limiting thresholds of 2.63 mJ/cm2 (RF) and 7.15 mJ/cm2 (PVD) confirm the superior limiting performance of the RF-sputtered In2S3 film for visible-range nonlinear photonic applications.