In Situ Monitoring of Crystallinity of FeSe2 Thin Films During Thermal Annealing and the Annealing Effects on the Structural, Optical and Dielectric Properties
Yükleniyor...
Tarih
04/07/2025
Dergi Başlığı
Dergi ISSN
Cilt Başlığı
Yayıncı
Crystal Research and Technology, Wiley
Erişim Hakkı
info:eu-repo/semantics/embargoedAccess
Özet
Herein stacked layers of iron selenide (FeSe2) thin films are deposited by the
physical evaporation technique and thermally annealed. An in situ monitoring
of the crystallinity during the annealing process has shown that the
crystallinity is reached at 100 °C. The crystallinity of the films that preferred
the orthorhombic phase is enhanced with increasing annealing temperature.
Evidences about the improved crystallinity are presented by the increased
crystallite and grain sizes, decreased microstrain values, decreased stacking
faults, and decreased defect densities with increasing annealing temperature.
Optical investigations have shown impressive effect of the annealing process
on the optical reflectance, optical contrast, and light absorbability. Namely,
respective improvement percentages exceeding 170%, 64%, and 140% is
achieved near E≈2 eV for samples annealed at 200 °C for 20 min. Both direct
and indirect optical transitions are dominant in the film. In addition the
annealing increased the dielectric constant in the spectral range of 1.17–4.20
eV. Maximum dielectric enhancement by 214% is reached near ≈2.10 eV.
Moreover, the annealing process increases the optical conductivity and drift
mobility of the FeSe2 films. The improvement in the crystallinity that resulted
in enhanced optical properties makes the thermally annealed FeSe2 films
promising for optoelectronic technology applications.
Açıklama
Anahtar Kelimeler
dielectric, enhanced optical conduction, FeSe2, orthorhombic, thermal annealing
Kaynak
Crystal Research and Technology,
WoS Q Değeri
Scopus Q Değeri
Cilt
59
