Temperature-dependent optical characteristics of sputtered Ga-doped ZnO thin films

Gullu H. H., Isik M., Hasanlı N., Parlak M.

MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS, cilt.263, 2021 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 263
  • Basım Tarihi: 2021
  • Doi Numarası: 10.1016/j.mseb.2020.114834
  • Dergi Adı: MATERIALS SCIENCE AND ENGINEERING B-ADVANCED FUNCTIONAL SOLID-STATE MATERIALS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Chemical Abstracts Core, Communication Abstracts, INSPEC, Metadex, Civil Engineering Abstracts
  • Anahtar Kelimeler: Ga-doped ZnO, Optical properties, Sputtering
  • Orta Doğu Teknik Üniversitesi Adresli: Evet

Özet

The present paper reports structural and optical properties of gallium (Ga) doped ZnO thin films (GZO) grown by magnetron sputtering technique. The crystalline properties were determined from X-ray diffraction measurements and analyses pointed out the crystalline structure as hexagonal, crystalline size as 43 nm and strain as 6.9 x 10(-5). Derivative spectroscopy analyses showed that band gap energy of GZO thin films decreases from 3.50 eV (10 K) to 3.45 eV (300 K). Temperature-band gap energy dependency was analyzed using Varshni and O'DonnellChen models. The absolute zero band gap energy, the rate of change of band gap energy with temperature and phonon energy were found as 3.50 eV, -2.8 x 10(-4) eV/K and 15 meV, respectively. The room temperature band gap and Urbach energies were also determined as 3.43 eV and 102 meV, respectively, from the absorption analysis.