Browsing by Author "Mermer, O"

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    A Numerical Analysis of Thermal Management Schemes of a LED Array in TFT TV
    Mermer, O; Nil, M; Akgul, MB
    This paper aims to perform the numerical analysis and to investigate thermal characteristics of the LED backlight TFT TV according to thermal design parameters. Natural convective cooling of a LED array system used TFT TV is considered in this study. Numerical computations are carried out for horizontal and vertical orientations of the LED array. The effects of the PCB materials on the temperature distribution are discussed in detail. It is found that the maximum temperature of the LED packages significantly decreases by the horizontal orientation of the LED array in TFT based television. In addition, ceramic based PCB materials having high thermal conductivity such as A1N present better thermal performance than that of metal based PCB materials.
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    Experimental and computational investigation of graphene/SAMs/n-Si Schottky diodes
    Aydin, H; Bacaksiz, C; Yagmurcukardes, N; Karakaya, C; Mermer, O; Can, M; Senger, RT; Sahin, H; Selamet, Y
    We have investigated the effect of two different self-assembled monolayers (SAMs) on electrical characteristics of bilayer graphene (BLG)/n-Si Schottky diodes. Novel 4bis(diphenylamino)-1, 1':3-terpheny1-5' carboxylic acids (TPA) and 4,4-di-9H-carbazol-9-y1-1,1':3'1'-terpheny1-5' carboxylic acid (CAR) aromatic SAMs have been used to modify n-Si surfaces. Cyclic voltammetry (CV) and Kelvin probe force microscopy (KPFM) results have been evaluated to verify the modification of n-Si surface. The current-voltage (I-V) characteristics of bare and SAMs modified devices show rectification behaviour verifying a Schottky junction at the interface. The ideality factors (n) from ln(I)-V dependences were determined as 2.13,1.96 and 2.07 for BLG/n-Si, BLG/TPA/n-Si and BLG/CAR/n-Si Schottky diodes, respectively. In addition, Schottky barrier height (SBH) and series resistance (Rs) of SAMs modified diodes were decreased compared to bare diode due to the formation of a compatible interface between graphene and Si as well as n-n interaction between aromatic SAMs and graphene. The CAR-based device exhibits better diode characteristic compared to the TPA-based device. Computational simulations show that the BLG/CAR system exhibits smaller energy-level-differences than the BLG/TPA, which supports the experimental findings of a lower Schottky barrier and series resistance in BLG/CAR diode. (C) 2017 Elsevier B.V. All rights reserved.