Yazar "Basol, B. M." seçeneğine göre listele

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    Alloying and phase transformation in CdS/CdSe bilayers annealed with or without CdCl2
    (Elsevier Sci Ltd, 2019) Ciris, A.; Basol, B. M.; Yilmaz, S.; Atasoy, Y.; Tomakin, M.; Kucukomeroglu, T.; Bacaksiz, E.
    The present paper studies the structural, compositional, morphological and optical properties of thin CdS/CdSe stacks annealed in an inert atmosphere or subjected to a CdCl2 treatment. The bilayer stacks were fabricated by chemical bath deposition (CBD) of a 50 nm thick CdS layer followed by evaporation of a CdSe film with equal thickness. It was found that when this stack was annealed at 400 degrees C for up to 10 min, no appreciable intermixing/alloying between the two layers was detected. Upon heating for 5-10 min in presence of a CdCl2 layer disposed over the CdSe film, however, led to appreciable alloying and formation of CdSSe, which was confirmed through XRD, optical transmission and room temperature photoluminescence measurements. XRD data further showed that the CdS layer in the CdS/CdSe stack had nano-amorphous structure that did not change upon annealing in inert atmosphere. The CdSe layer of the stack, which had a cubic structure, also preserved its phase upon annealing in inert atmosphere. When the CdS/CdSe stack was CdCl2 treated, the phase of the CdSSe alloy formed was transformed to hexagonal. These observations may have consequences in applications where CdS/CdSe bilayers are formed within device structures and subjected to various types of heat treatments.
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    CdCl2 treatment and its role in enhancing photodetection properties of CdTe and Cd1-xZnxTe films
    (Elsevier, 2025) Yilmaz, S.; Basol, B. M.; Polat, I.; Daday, M. Taykurt; Tomakin, M.; Kucukomeroglu, T.; Bacaksiz, E.
    Close space sublimated CdTe and Cd1-xZnxTe (CZT) films were grown on glass substrates and CdCl2 activation was applied on these films to improve their physical, optical and electrical characteristics for photodetector applications. X-ray diffraction data showed that CdCl2 treatment of CdTe caused a reduction in the dislocation density and microstrain, whereas Zn incorporation/CdCl2 treatment slightly increased these values compared to the as-deposited CdTe films. Morphological examination indicated that CdCl2 activation transformed grains from faceted to rounded shape for both CdTe and CZT films. A band gap enlargement was observed from 1.45 eV to 1.47 eV for both CdTe and CZT films upon CdCl2 treatment. CdCl2-treated CZT films were used to fabricate photodetectors that exhibited the highest performance with a rise/fall time of 27/28 ms, sensitivity of 1301 %, responsivity of 0.0143 A/W, detectivity of 5.7x107 Jones and external quantum efficiency of 4.0 % under blue light illumination at 2 V.
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    Comparative analysis of chloride-treated ZnTe films in photodetector devices
    (Elsevier Sci Ltd, 2025) Yilmaz, S.; Basol, B. M.; Olgar, M. A.; Bayazit, T.; Kucukomeroglu, T.; Bacaksiz, E.
    The current work aims to demonstrate the potential effects of different Cl-treatments on ZnTe thin films as candidates for photodetector applications. X-ray diffraction (XRD) data revealed that the degree of preferred orientation along the (111) plane increased with Cl-treatments compared to the as-deposited ZnTe, and Cltreatment also promoted crystal growth in ZnTe. Surface images showed that the MgCl2-treated ZnTe sample exhibited a transformation of faceted grains into rounded shapes, resulting in a denser and more compact microstructure. Among the samples, the CdCl2-treated ZnTe demonstrated a sharper transition. The optical band gaps were 2.18 eV for the as-deposited ZnTe film, 2.16 eV for the ZnCl2-treated sample, 2.20 eV for the CdCl2-treated sample, and 2.19 eV for the MgCl2-treated sample. This indicates that ZnCl2 treatment slightly lowers the band gap, whereas CdCl2 and MgCl2 treatments lead to small increases. The current-voltage (I-V) curves displayed a steeper slope under both dark and illuminated conditions after ZnCl2, MgCl2, and CdCl2 treatments compared to the as-deposited ZnTe, likely due to enhanced conductivity. The CdCl2-treated ZnTe photodetectors (PDs) exhibited the fastest photoresponse, with rise and fall times of 13 m s each. Furthermore, CdCl2-treated ZnTe-based PDs achieved the highest sensitivity (S = 417 %), responsivity (R = 0.0024 A/W), and detectivity (D* = 1.4 x 107Jones) among the tested devices, suggesting that these PDs are suitable candidates for highperformance photodetector applications.