Mecit G., Işık M., Hasanlı N.
MATERIALS RESEARCH EXPRESS, cilt.13, sa.12, ss.1, 2026 (SCI-Expanded, Scopus)
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Yayın Türü:
Makale / Tam Makale
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Cilt numarası:
13
Sayı:
12
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Basım Tarihi:
2026
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Doi Numarası:
10.1088/2053-1591/ae7af9
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Dergi Adı:
MATERIALS RESEARCH EXPRESS
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Derginin Tarandığı İndeksler:
Scopus, Materials Science & Engineering Collection (ProQuest), Technology Collection (ProQuest), Science Citation Index Expanded (SCI-EXPANDED), Chemical Abstracts Core, Compendex, INSPEC, Directory of Open Access Journals
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Sayfa Sayıları:
ss.1
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TED Üniversitesi Adresli:
Evet
Özet
Abstract
Layered GaS is increasingly considered for ultraviolet optoelectronics, van der Waals nanophotonics, and nonlinear optical platforms; however, a self-consistent bulk dielectric reference connecting its dispersion, absorption, optical-conductivity, and energy-loss response remains limited. Here, we report the room-temperature effective pseudo-dielectric response of Bridgman-grown bulk GaS single crystals determined by spectroscopic ellipsometry over the photon-energy range 1.2–6.0 eV. From freshly cleaved (001) surfaces, the refractive index, extinction coefficient, absorption coefficient, optical conductivity, and surface/volume energy-loss functions are extracted within a unified framework. First-derivative analysis of the absorption coefficient identifies the indirect absorption onset at approximately 2.47 eV, consistent with previous optical benchmarks. In the transparent spectral region, the Wemple–DiDomenico single-effective-oscillator model yields
E
0
≈
6.01
eV,
E
d
≈
34.6
eV, and a static refractive index of
n
0
≈
2.60
. Pronounced optical-conductivity features near 3.9 and 5.3 eV are discussed in relation to previously established interband critical-point transitions. In addition, order-of-magnitude third-order nonlinear optical parameters are estimated using Miller’s generalized rule and are presented strictly as guides for nonlinear-experiment design. The resulting dataset provides an effective ordinary-channel bulk reference for modeling GaS-based UV photodetectors, reconfigurable phase-change photonic components, nonlinear optical elements, and high-refractive-index van der Waals nanophotonic structures.