WoS İndeksli Yayınlar Koleksiyonu / WoS Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7150

Browse

Filters

20172

Settings

Author: search.filters.author.Olgar, Mehmet AliSubject: search.filters.subject.Kesterite

Search Results

Now showing 1 - 2 of 2
  • Article
    Citation - WoS: 51
    Citation - Scopus: 48
    Cu2znsns4-Based Thin Films and Solar Cells by Rapid Thermal Annealing Processing
    (Elsevier Ltd., 2017) Olgar, Mehmet Ali; Özyüzer, Lütfi; Mainz, R.; Özyüzer, Lütfi; Unold, T.; 04.05. Department of Pyhsics; 04. Faculty of Science; 01. Izmir Institute of Technology
    In this study, kesterite Cu2ZnSnS4 (CZTS) absorber layers were fabricated by DC magnetron sputtering deposition of metallic Cu-Zn-Sn precursors, followed by an annealing treatment in sulfur vapor atmosphere at 600 °C for 3 min using rapid thermal processing (RTP). Three types of stacked metallic films were prepared and included pre-annealing of Cu-Sn stacks in order to induce preferential Cu-Sn alloying. The chemical composition of the sulfurized films was obtained by X-ray fluorescence (XRF) before and after etching the samples in KCN solution. All CZTS thin films are found to be Cu-poor and Zn-rich. Structural characterizations were performed by X-ray diffraction (XRD) and Raman spectroscopy to investigate the impact of pre-annealing on the structural properties of the precursors and final CZTS films. Glow discharge optical emission spectroscopy (GDOES) shows that pre-annealing of the precursors can improve depth homogeneity of the CZTS films. Photoluminescence spectra and the optical band gap energy values are compatible with literature. Selected samples were processed to solar cells and characterized.
  • Article
    Citation - WoS: 22
    Citation - Scopus: 23
    Effect of Heat Treating Metallic Constituents on the Properties of Cu2znsnse4 Thin Films Formed by a Two-Stage Process
    (Elsevier Ltd., 2017) Olgar, Mehmet Ali; Başol, B. M.; Aygün, Gülnur; Özyüzer, Lütfi; Aygün, Gülnur; Özyüzer, Lütfi; Bacaksız, Emin; 04.05. Department of Pyhsics; 04. Faculty of Science; 01. Izmir Institute of Technology
    In this study Cu2ZnSnSe4 (CZTSe) thin films were grown by a two-stage process that involved sputter deposition of a Cu/Sn/Zn/Cu metallic stack, annealing the stack at various temperatures for 30 min, evaporation of a Se cap over the metallic stack thus forming a precursor layer, and subjecting the precursor layer to a final high temperature reaction step at 550 °C. Different samples were prepared with annealing temperatures of the metallic stacks ranging from 200 °C to 350 °C. The results showed that heat treatment of the metallic stacks did not cause much change in their morphology and elemental composition, however their phase content changed noticeably when the anneal temperature was raised to 250 °C. Specifically, while the metallic films were dominated by CuSn and Cu5Zn8 phases at low temperatures, the dominant phase shifted to Cu6Sn5 at the annealing temperature of 250 °C and higher. Also formation of a distinct Cu3Zn2 phase was observed upon annealing at temperatures at or above 250 °C. After reaction with Se, the CZTSe layer obtained from the metallic film, which was annealed at 250 °C was found to be the best n terms of its composition, crystalline quality and purity, although it contained a small amount of CuSe. The other layers were found to contain small amounts of other secondary phases such as SnSe, CuSe2, ZnSe and Cu2SnSe3. SEM micrographs showed denser structure for CZTSe layers grown from metallic films annealed at or above 250 °C. Optical band gap, resistivity and carrier concentration of the best quality CZTSe film were found to be about 0.87 eV, 2 Ω-cm and 4 × 1017 cm− 3, respectively.