Browsing by Author "Ozgit Akgun, C."
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Current transport mechanisms in plasma-enhanced atomic layer deposited AlN thin films
Altuntas, H.; Ozgit Akgun, C.; Donmez, I.; Bıyıklı, Necmi (A I P Publishing LLC, 2015)Here, we report on the current transport mechanisms in AlN thin films deposited at a low temperature (i.e., 200°C) on p-type Si substrates by plasma-enhanced atomic layer deposition. Structural characterization of the ... -
Effect of film thickness on the electrical properties of AlN films prepared by plasma-enhanced atomic layer deposition
Altuntas, H.; Ozgit Akgun, C.; Donmez, I.; Bıyıklı, Necmi (Institute of Electrical and Electronics Engineers Inc., 2015)In this paper, AlN thin films with two different thicknesses, i.e., 7 and 47 nm, were deposited at 200 °C on p-type Si substrates by plasma-enhanced atomic layer deposition using trimethylaluminum and ammonia. To investigate ... -
Effect of O2/Ar flow ratio and post-deposition annealing on the structural, optical and electrical characteristics of SrTiO3 thin films deposited by RF sputtering at room temperature
Goldenberg, E.; Bayrak, T.; Ozgit Akgun, C.; Haider A.; Leghari, S.A.; Kumar, M.; Bıyıklı, Necmi (Elsevier, 2015)SrTiO3 (STO) thin films have been prepared by reactive RF magnetron sputtering on Si (100) and UV fused silica substrates at room temperature. The effect of oxygen flow on film characteristics was investigated at a total ... -
Effect of reactor pressure on optical and electrical properties of InN films grown by high-pressure chemical vapor deposition
Alevli, M.; Gungor, N.; Alkis, S.; Ozgit Akgun, C.; Donmez, I.; Okyay, Ali Kemal; Gamage, S.; Senevirathna, I.; Dietz, N.; Bıyıklı, Necmi (Wiley - V C H Verlag GmbH & Co. KGaA, 2015)The influences of reactor pressure on the stoichiometry, free carrier concentration, IR and Hall determined mobility, effective optical band edge, and optical phonon modes of HPCVD grown InN films have been analysed and ... -
Electrical characteristics of β-Ga2O3 thin films grown by PEALD
Altuntas, H.; Donmez, I.; Ozgit Akgun, C.; Bıyıklı, Necmi (Elsevier, 2014)In this work, 7.5 nm Ga2O3 dielectric thin films have been deposited on p-type (1 1 1) silicon wafer using plasma enhanced atomic layer deposition (PEALD) technique. After the deposition, Ga2O 3 thin films were annealed ... -
Electronic and optical device applications of hollow cathode plasma assisted atomic layer deposition based GaN thin films
Bolat, S.; Tekcan, B.; Ozgit Akgun, C.; Bıyıklı, Necmi; Okyay, Ali Kemal (A I P Publishing LLC, 2015)Electronic and optoelectronic devices, namely, thin film transistors (TFTs) and metal-semiconductor-metal (MSM) photodetectors, based on GaN films grown by hollow cathode plasma-assisted atomic layer deposition (PA-ALD) ... -
Enhanced photocatalytic activity of homoassembled ZnO nanostructures on electrospun polymeric nanofibers: a combination of atomic layer deposition and hydrothermal growth
Kayaci, F.; Vempati S.; Ozgit Akgun, C.; Bıyıklı, Necmi; Uyar, Tamer (Elsevier, 2014)We report on the synthesis and photocatalytic activity (PCA) of electrospun poly(acrylonitrile) (PAN) nanofibrous mat decorated with nanoneedles of zinc oxide (ZnO). Apart from a detailed morphological and structural ... -
Fabrication of AlN/BN bishell hollow nanofibers by electrospinning and atomic layer deposition
Haider A.; Ozgit Akgun, C.; Kayaci, F.; Okyay, Ali Kemal; Uyar, Tamer; Bıyıklı, Necmi (AIP Publishing, 2014-09-08)Aluminum nitride (AlN)/boron nitride (BN) bishell hollow nanofibers (HNFs) have been fabricated by successive atomic layer deposition (ALD) of AlN and sequential chemical vapor deposition (CVD) of BN on electrospun polymeric ... -
Fabrication of flexible polymer–GaN core–shell nanofibers by the combination of electrospinning and hollow cathode plasma-assisted atomic layer deposition
Ozgit Akgun, C.; Kayaci, F.; Vempati S.; Haider A.; Celebioglu A.; Goldenberg, E.; Kizir S.; Uyar, Tamer; Bıyıklı, Necmi (Royal Society of Chemistry, 2015)Here we demonstrate the combination of electrospinning and hollow cathode plasma-assisted atomic layer deposition (HCPA-ALD) processes by fabricating flexible polymer-GaN organic-inorganic core-shell nanofibers at a ... -
Hollow cathode plasma-assisted atomic layer deposition of crystalline AlN, GaN and AlxGa1−xN thin films at low temperatures
Ozgit Akgun, C.; Goldenberg, E.; Okyay, Ali Kemal; Bıyıklı, Necmi (Royal Society of Chemistry, 2014)The authors report on the use of hollow cathode plasma for low-temperature plasma-assisted atomic layer deposition (PA-ALD) of crystalline AlN, GaN and AlxGa1 xN thin films with low impurity concentrations. Depositions ... -
Low temperature thin films transistors with hollow cathode plasma-assisted atomic layer deposition based GaN channels
Bolat, S.; Ozgit Akgun, C.; Tekcan, B.; Bıyıklı, Necmi; Okyay, Ali Kemal (AIP Publishing LLC, 2014)We report GaN thin film transistors (TFT) with a thermal budget below 250 °C. GaN thin films are grown at 200 °C by hollow cathode plasma-assisted atomic layer deposition (HCPA-ALD). HCPA-ALD-based GaN thin films are found ... -
Low-Temperature Deposition of Hexagonal Boron Nitride via Sequential Injection of Triethylboron and N2/H2 Plasma
Haider A.; Ozgit Akgun, C.; Goldenberg, E.; Okyay, Ali Kemal; Bıyıklı, Necmi (Wiley-Blackwell Publishing, Inc., 2014)Hexagonal boron nitride (hBN) thin films were deposited on silicon and quartz substrates using sequential exposures of triethylboron and N 2 /H 2 plasma in a hollow-cathode plasma- assisted atomic layer deposition reactor ... -
Low-temperature grown wurtzite InxGa1−xN thin films via hollow cathode plasma-assisted atomic layer deposition
Haider A.; Kizir S.; Ozgit Akgun, C.; Goldenberg, E.; Leghari, S. A.; Okyay, Ali Kemal; Bıyıklı, Necmi (Royal Society of Chemistry, 2015-08)Herein, we report on atomic layer deposition of ternary InxGa1−xN alloys with different indium contents using a remotely integrated hollow cathode plasma source. Depositions were carried out at 200 °C using organometallic ... -
Low-temperature hollow cathode plasma-assisted atomic layer deposition of crystalline III-nitride thin films and nanostructures
Ozgit Akgun, C.; Goldenberg, E.; Bolat, S.; Tekcan, B.; Kayaci, F.; Uyar, Tamer; Okyay, Ali Kemal; Bıyıklı, Necmi (Wiley - V C H Verlag GmbH & Co. KGaA, 2015)Hollow cathode plasma-assisted atomic layer deposition (HCPA-ALD) is a promising technique for obtaining III-nitride thin films with low impurity concentrations at low temperatures. Here we report our previous and current ... -
Low-temperature sequential pulsed chemical vapor deposition of ternary BxGa1-xN and BxIn1-xN thin film alloys
Haider A.; Kizir S.; Ozgit Akgun, C.; Okyay, Ali Kemal; Bıyıklı, Necmi (AVS Science and Technology Society, 2016)In this work, the authors have performed sequential pulsed chemical vapor deposition of ternary BxGa1-xN and BxIn1-xN alloys at a growth temperature of 450 °C. Triethylboron, triethylgallium, trimethylindium, and N2 or ... -
Metal-semiconductor-metal ultraviolet photodetectors based on gallium nitride grown by atomic layer deposition at low temperatures
Tekcan, B.; Ozgit Akgun, C.; Bolat, S.; Bıyıklı, Necmi; Okyay, Ali Kemal (SPIE, 2014)Proof-of-concept, first metal-semiconductor-metal ultraviolet photodetectors based on nanocrystalline gallium nitride (GaN) layers grown by low-temperature hollow-cathode plasma-assisted atomic layer deposition are ... -
Selective isolation of the electron or hole in photocatalysis: ZnO–TiO2 and TiO2–ZnO core–shell structured heterojunction nanofibers via electrospinning and atomic layer deposition
Kayaci, F.; Vempati S.; Ozgit Akgun, C.; Donmez, I.; Bıyıklı, Necmi; Uyar, Tamer (Royal Society of Chemistry, 2014-02-06)Heterojunctions are a well-studied material combination in photocatalysis studies, the majority of which aim to improve the efficacy of the catalysts. Developing novel catalysts begs the question of which photo-generated ... -
Surface ionic states and structure of titanate nanotubes
Vempati S.; Kayaci-Senirmak, F.; Ozgit Akgun, C.; Bıyıklı, Necmi; Uyar, Tamer (Royal Society of Chemistry, 2015)Here we present an investigation on Zn-Ti-O ternary (zinc titanate) nanostructures which were prepared by a combination of electrospinning and atomic layer deposition. Depending on the ZnO and TiO2 molar ratio, two titanates ... -
Transformation of polymer-ZnO core-shell nanofibers into ZnO hollow nanofibers: Intrinsic defect reorganization in ZnO and its influence on the photocatalysis
Kayaci, F.; Vempati S.; Ozgit Akgun, C.; Donmez, I.; Bıyıklı, Necmi; Uyar, Tamer (Elsevier, 2015)Photocatalytic activity (PCA) on semiconductors is known to be majorly influenced by specific surface area and intrinsic lattice defects of the catalyst. In this report, we tested the efficiencies of 1D ZnO catalysts of ... -
Water-soluble non-polymeric electrospun cyclodextrin nanofiber template for the synthesis of metal oxide tubes by atomic layer deposition
Celebioglu A.; Vempati S.; Ozgit Akgun, C.; Bıyıklı, Necmi; Uyar, Tamer (Royal Society of Chemistry, 2014)We report on the suitability of water-soluble non-polymeric electrospun cyclodextrin (CD) nanofiber templates by using atomic layer deposition (ALD) to yield metal oxide tubes. To demonstrate this, water-soluble electrospun ...