Scopus İndeksli Yayınlar Koleksiyonu / Scopus Indexed Publications Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7148

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Author: search.filters.author.İyikanat, FadılPublisher: search.filters.publisher.Elsevier

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  • Article
    Citation - WoS: 20
    Citation - Scopus: 23
    Kagome-Like Silicene: a Novel Exotic Form of Two-Dimensional Epitaxial Silicon
    (Elsevier, 2020) Sassa, Yasmine; Johansson, Fredrik O. L.; Lindblad, Andreas; Yazdi, Milad G.; Simonov, Konstantin; Weissenrieder, Jonas; Le Lay, Guy; İyikanat, Fadıl; Şahin, Hasan
    Since the discovery of graphene, intensive efforts have been made in search of novel two-dimensional (2D) materials. Decreasing the materials dimensionality to their ultimate thinness is a promising route to unveil new physical phenomena, and potentially improve the performance of devices. Among recent 2D materials, analogs of graphene, the group IV elements have attracted much attention for their unexpected and tunable physical properties. Depending on the growth conditions and substrates, several structures of silicene, germanene, and stanene can be formed. Here, we report the synthesis of a Kagome-like lattice of silicene on aluminum (1 1 1) substrates. We provide evidence of such an exotic 2D Si allotrope through scanning tunneling microscopy (STM) observations, high-resolution core-level (CL) and angle-resolved photoelectron spectroscopy (ARPES) measurements, along with Density Functional Theory calculations.
  • Article
    Citation - WoS: 50
    Citation - Scopus: 52
    Monitoring the Characteristic Properties of Ga-Doped Zno by Raman Spectroscopy and Atomic Scale Calculations
    (Elsevier, 2019) Horzum, Şeyda; İyikanat, Fadıl; Senger, Ramazan Tuğrul; Çelebi, Cem; Sbeta, Mohamed; Yıldız, Abdullah; Serin, Tülay
    We experimentally and theoretically study how the structural and vibrational properties of zinc oxide (ZnO) are modified upon Gallium (Ga) doping. The characteristics of Ga-doped ZnO thin films which are synthesized by sol-gel spin coating method on glass substrates are monitored by using X-ray diffraction (XRD) and Raman scattering measurements. For atomic-level understanding of the experimental findings state-of-the-art density functional theory (DFT) based calculations are also performed. DFT calculations reveal that both the substitution and adsorption of Ga atoms in ZnO are energetically possible and substitutional doping in ZnO is the most favourable scenario. XRD measurements show that all the films are in wurtzite structure and the crystallite size of the films decreases with increasing Ga doping. In addition, Raman analysis show that strong vibrational modes at about 100 and 441 cm(-1) are associated with E-2(low) and E-2(high) phonon branches of ZnO, respectively. While the frequency of the E-2(low) mode downshifts with increasing Ga concentration, the E-2(high) phonon mode is not affected by the Ga doping. Furthermore, E-Ga phonon branch, stemming from the substituted Ga atoms, emerges at low frequencies. It is also seen that the Raman intensity of the E-G(a) peak linearly increases with increasing Ga concentration. Experimental results on the vibrational properties are in good agreement with the ab initio phonon calculations. (C) 2018 Elsevier B.V. All rights reserved.
  • Article
    Citation - WoS: 13
    Citation - Scopus: 12
    Orthorhombic Cspbi3 Perovskites: Thickness-Dependent Structural, Optical and Vibrational Properties
    (Elsevier, 2020) Özen, Sercan; İyikanat, Fadıl; Özcan, Mehmet; Tekneci, Gülsüm Efsun; Eren, İsmail; Sözen, Yiğit; Şahin, Hasan
    Cesium lead halide perovskites have been subject to intense investigation, mostly because of their potential to be used in optoelectronic device applications. However, regarding the need for nanoscale materials in forthcoming nanotechnology applications, understanding of how the characteristic properties of these perovskite crystals are modified through dimensional crossover is essential. In this study, thickness-dependence of the structural, electronic and vibrational properties of orthorhombic CsPbI3, which is one of the most stable phase at room temperature, is investigated by means of state-of-the-art first-principles calculations. Our results show that (i) bilayers and monolayers of CsPbI3 can be stabilized in orthorhombic crystal symmetry, (ii) among; the possible ultra-thin perovskites only structures with CsI-terminated surface are dynamically stable (iii) electronic band gap increases with decrease in perovskite thickness due to quantum size effect and (iv) reflectivity and transmissivity of the orthorhombic CsPbI3 can be tuned by varying the thickness that modifies the electron confinement. (c) 2019 Elsevier B.V. All rights reserved.