Yazar "Manfo, Theodore Azemtsop" seçeneğine göre listele

Listeleniyor 1 - 2 / 2
  • Küçük Resim Yok
    Öğe
    The light detection performance of Al/VNPB/n-Si Schottky photodetectors for a wide-range spectrum
    (Elsevier, 2026) Yildiz, Dilber Esra; Manfo, Theodore Azemtsop; Hussaini, Ali Akbar; Yildirim, Murat; Gunduz, Bayram
    A novel organic-inorganic Schottky photodetector incorporating a N4, N4 '-di(Naphthalen-1-yl)-N4, N4 '-bis(4-vinylphenyl)biphenyl-4,4 '-diamine (VNPB) thin film interlayer was fabricated and systematically characterized. The Al/VNPB/n-Si Schottky photodetectors were investigated using UV-Vis spectroscopy, X-ray diffraction (XRD), and scanning electron microscopy (SEM), revealing strong visible light absorption and high crystallinity. Electrical measurements under varying illumination intensities demonstrated enhanced rectification and significant photocurrent generation, attributed to thermionic emission and efficient photocarrier formation. Under solar illumination (20-100 mW/cm(2)), the device demonstrated strong photocurrent generation, high photosensitivity (22.05-80.58), responsivity up to 2.18 A/W, and detectivity values on the order of 10(10) Jones, confirming efficient low-noise photodetection. The device exhibited high photosensitivity, responsivity, and specific detectivity across a broad spectral range (351-1600 nm), with peak performance at 600 nm, where a maximum responsivity of 0.0366 A/W, an external quantum efficiency of similar to 75%, and a detectivity of 6.11 x 10(9) Jones were achieved. In addition, strong near-infrared performance was observed at 1000 nm, with a photosensitivity of 4.85 and a detectivity of 5.76 x 10(9) Jones. Compared to oxide-based photodetectors, the Al/VNPB/n-Si architecture demonstrated superior optoelectronic performance, positioning VNPB as a promising interfacial material for next-generation photodetection technologies.
  • Küçük Resim Yok
    Öğe
    The light detection performance of the Al/DCJTB/n-Si Schottky type photodetector for a wide-range spectrum
    (Elsevier, 2026) Manfo, Theodore Azemtsop; Yildiz, Dilber Esra; Hussaini, Ali Akbar; Yildirim, Murat; Gunduz, Bayram
    The 4-(dicyanomethylene)-2-t-butyl-6-(1,1,7,7-tetramethyljulolidyl-9-enyl)-4H-pyran (DCJTB) is a red fluorescent dye known for its high luminescence efficiency, color purity, and resistance to concentration quenching. DCJTB was applied as an interfacial layer between Si and Al via spin coating to investigate its effect on Schottky photodetector performance at various light intensities and wavelengths (UV-Vis-NIR). Structural and optical properties of the DCJTB layer were characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and ultraviolet-visible (UV-vis) spectroscopy. Current-voltage (I-V) and current-time (I-t) measurements revealed that the Al/DCJTB/n-Si heterojunction exhibits an ideality factor (n) of 3.15 and a barrier height (Phi b) of 0.701 eV under dark conditions. With increasing illumination (20-100 mW/cm2), n varied from 3.884 to 3.077, while the barrier height increased slightly. The device achieved a responsivity (R) of 0.63 A/W and a specific detectivity of 1.63 x 1010 Jones under sunlight. The external quantum efficiency (EQE) reached 0.68 % at 550 nm, confirming high sensitivity in the green region, while performance declined beyond 700 nm. These findings demonstrate that the Al/DCJTB/n-Si heterojunction is most effective in the visible spectrum, making it promising for optoelectronic and photodetection applications.