Physics / Fizik

Permanent URI for this collectionhttps://hdl.handle.net/11147/6

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Author: search.filters.author.Ekmekçioğlu, MerveSubject: search.filters.subject.Thin films

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  • Article
    Citation - WoS: 2
    Citation - Scopus: 2
    In-Situ Thin Film Copper-Copper Thermocompression Bonding for Quantum Cascade Lasers
    (Springer, 2021) Rouhi, Sina; Özdemir, Mehtap; Demirhan, Yasemin; Yiğen, Serap; Demirhan, Yasemin; Yiğen, Serap; Kosiel, Kamil; Kozubal, Maciej; Özdemir, Mehtap; Aygün, Gülnur; Özyüzer, Lütfi; Reno, John L.; Aygün, Gülnur; Özyüzer, Lütfi; 04.05. Department of Pyhsics; 04. Faculty of Science; 01. Izmir Institute of Technology
    The choice of metals, bonding conditions and interface purity are critical parameters for the performance of metal-metal bonding quality for quantum cascade lasers (QCLs). Here, we present a novel approach for the thermocompression bonding of Cu-Cu thin films on GaAs-based waveguides without having any oxide phase, contamination or impurities at the interface. We designed a hybrid system in which magnetron sputtering of Ta, thermal evaporation of Cu and Cu-Cu thermocompression bonding processes can be performed sequentially under high vacuum conditions. GaAs/Ta/Cu and Cu/Ta/GaAs structures were thermocompressionally bonded in our in-situ homebuilt bonding system by optimizing the deposition parameters and bonding conditions. The grown thin film and the obtained interfaces were characterized using x-ray diffraction (XRD), scanning electron microscopy (SEM) and energy-dispersive x-ray spectroscopy (EDX) techniques. The optimum Ta and Cu films' thicknesses were found to be about 20 nm and 500 nm, respectively. EDX analysis showed that the Ta thin film interlayer diffused into the Cu structure, providing better adhesivity and rigidity for the bonding. Additionally, no oxidation phases were detected at the interface. The best bonding quality was obtained when heated up to 430 degrees C with an applied pressure of 40 MPa during bonding process.
  • Article
    Citation - WoS: 3
    Citation - Scopus: 3
    Compact Multilayer Thin-Film Color Filters and Direct Integration on White-Light Diodes for Color Conversion
    (Optical Society of America, 2021) Yiğen, Serap; Aygün, Gülnur; Ekmekçioğlu, Merve; Yiğen, Serap; Özdemir, Mehtap; Özdemir, Mehtap; Aygün, Gülnur; Özyüzer, Lütfi; Özyüzer, Lütfi; 04.05. Department of Pyhsics; 04. Faculty of Science; 01. Izmir Institute of Technology
    We present highly efficient green, yellow, and red filters based on a metal-dielectric structure. The filters encompass only five layers of alternating zinc tin oxide and silver thin films that are grown on soda lime glass and white light-emitting diodes (LEDs) using direct current magnetron sputtering at room temperature. The designed filters provide efficient color filtering in the visible spectrum. High purity colored light is obtained by direct application of filters on LEDs as color converters. The presented method offers an easy way for realizing different colors by tuning the thicknesses of layers in the structure. (C) 2021 Optical Society of America