Browsing by Author "Caliskan, D."
Now showing items 1-13 of 13
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Chemical Visualization of a GaN p-n junction by XPS
Caliskan, D.; Sezen H.; Özbay, Ekmel; Süzer, Şefik (Nature Publishing Group, 2015)We report on an operando XPS investigation of a GaN diode, by recording the Ga2p 3/2 peak position under both forward and reverse bias. Areal maps of the peak positions under reverse bias are completely decoupled with ... -
Co doping induced structural and optical properties of sol-gel prepared ZnO thin films
Gungor, E.; Gungor, T.; Caliskan, D.; Ceylan, A.; Özbay, Ekmel (Elsevier BV, 2014-11)The preparation conditions for Co doping process into the ZnO structure were studied by the ultrasonic spray pyrolysis technique. Structural and optical properties of the Co:ZnO thin films as a function of Co concentrations ... -
Effect of growth pressure on coalescence thickness and crystal quality of GaN deposited on 4H-SiC
Caban, P.; Strupinski, W.; Szmidt, J.; Wojcik, M.; Gaca, J.; Kelekci, O.; Caliskan, D.; Özbay, Ekmel (Elsevier, 2010-09-25)The influence of growth pressure on the coalescence thickness and the crystal quality of GaN deposited on 4HSiC by low pressure metalorganic vapor phase epitaxy was studied. It was shown that growth pressure has an impact ... -
Effects of rapid thermal annealing on the structural and local atomic properties of ZnO: Ge nanocomposite thin films
Ceylan, A.; Rumaiz, A. K.; Caliskan, D.; Ozcan, S.; Özbay, Ekmel; Woicik, J. C. (A I P Publishing LLC, 2015)We have investigated the structural and local atomic properties of Ge nanocrystals (Ge-ncs) embedded ZnO (ZnO: Ge) thin films. The films were deposited by sequential sputtering of ZnO and Ge thin film layers on z-cut quartz ... -
Growth of high crystalline quality semi-insulating GaN layers for high electron mobility transistor applications
Yu H.; Caliskan, D.; Özbay, Ekmel (2006)Semi-insulating character (sheet resistivity of 3.26 × 10 11 Ω/sq) of thick GaN layers was developed for AlGaN/GaN high electron mobility transistor (HEMT) applications on an AlN buffer layer. Electrical and structural ... -
Improvement of breakdown characteristics in AlGaN/GaN/AlxGa 1-xN HEMT based on a grading Al xGa 1-xN buffer layer
Yu, H.; Lisesivdin, S. B.; Ozturk, M.; Bolukbas, B.; Kelekci, O.; Ozturk, M. K.; Ozcelik, S.; Caliskan, D.; Cakmak, H.; Demirel, P.; Özbay, Ekmel (Wiley, 2010-08-03)To improve the breakdown characteristics of an AlGaN/GaN based high electron mobility transistor (HEMT) for high voltage applications, AlGaN/GaN/Al xGa 1-xN double heterostructure (DH-HEMTs) were designed and fabricated ... -
Location and visualization of working p-n and/or n-p junctions by XPS
Copuroglu, M.; Caliskan, D.; Sezen, H.; Özbay, Ekmel; Süzer, Şefik (Nature Publishing Group, 2016)X-ray photoelectron spectroscopy (XPS) is used to follow some of the electrical properties of a segmented silicon photodetector, fabricated in a p-n-p configuration, during operation under various biasing configurations. ... -
Low dark current and high speed ZnO metal–semiconductor–metal photodetector on SiO2/Si substrate
Caliskan, D.; Bütün, B.; Çakır, M. C.; Özcan, S.; Özbay, Ekmel (AIP Publishing, 2014)ZnO thin films are deposited by radio-frequency magnetron sputtering on thermally grown SiO2 on Si substrates. Pt/Au contacts are fabricated by standard photolithography and lift-off in order to form a metal-semiconductor-metal ... -
Metal-semiconductor-metal photodetector on as-deposited TiO2 thin films on sapphire substrate
Caliskan, D.; Butun, B.; Ozcan, S.; Özbay, Ekmel (AIP Publishing LLC, 2013-03-06)TiO2 thin films are prepared on c-plane sapphire substrates by the RF magnetron sputtering method. The performance of the Pt contact metal–semiconductor–metal (MSM) photodetector fabricated on as-deposited films is studied. ... -
Metalorganic chemical vapor deposition growth and thermal stability of the AllNN/GaN high electron mobility transistor structure
Yu, H.; Ozturk, M.; Demirel, P.; Cakmak, H.; Bolukbas, B.; Caliskan, D.; Özbay, Ekmel (IOP Publishing, 2011)The AlxIn1-xN barrier high electron mobility transistor (HEMT) structure has been optimized with varied barrier composition and thickness grown by metalorganic chemical vapor deposition. After optimization, a transistor ... -
Rapid and sensitive colorimetric ELISA using silver nanoparticles, microwaves and split ring resonator structures
Addae, S.A.; Pinard, M.A.; Caglayan H.; Cakmakyapan, S.; Caliskan, D.; Özbay, Ekmel; Aslan, K. (2010)We report a new approach to colorimetric Enzyme-Linked Immunosorbent Assay (ELISA) that reduces the total assay time to < 2 min and the lower-detection-limit by 100-fold based on absorbance readout. The new approach ... -
Spectral response modification of TiO2 MSM photodetector with an LSPR filter
Caliskan, D.; Butun, B.; Ozcan, S.; Özbay, Ekmel (Optical Society of America, 2014)We fabricated UVB filtered TiO2 MSM photodetectors by the localized surface plasmon resonance effect. A plasmonic filter structure was designed using FDTD simulations. Final filter structure was fabricated with Al ... -
Ultrafast and sensitive bioassay using split ring resonator structures and microwave heating
Caglayan, H.; Cakmakyapan, S.; Addae, S. A.; Pinard, M. A.; Caliskan, D.; Aslan, K.; Özbay, Ekmel (American Institute of Physics, 2010-08-30)In this paper, we have reported that split ring resonators (SRRs) structures can be used for bioassay applications in order to further improve the assay time and sensitivity. The proof-of-principle demonstration of the ...