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Both Polyvinylpyrrolidone (PVP) and matrix-polymer of carbon (C)-PVP fibers (Fs) composites were synthesized by using the electrospinning technique and deposited onto the p-Si wafers to obtain PVP Fs/p-Si and C-PVP Fs/p-Si devices. The ultraviolet/Visible (UV/Vis) photodetector performance of both devices was compared. Both devices gave self-powere...
Citations
... Yıldırım et al. used propolis between n-Si and Au for UV-photodetector, and they reached 0.113 A/W responsivity and 4.04 × 10 9 Jones detectivity values [31]. Havigh et al. employed matrix-polymer of carbon and polyvinylpyrrolidone (PVP) composites for UV-Vis photodetector applications, and they obtained 0.69 A/W responsivity, 5.60 × 10 10 Jones detectivity and 53.76 × 10 3 on-off ratio for UV region [32]. Imer et al. investigated Ru(II)-pydim complex as an interface layer between p-Si and Al for photodetection applications. ...
Silicene is a 2D monoatomic sheet of silicon and can be used for various applications such as degradation, therapy, and biosafety. Polyaniline (PANI) is a conducting polymer employed for electronic devices. In this study, we synthesized PANI–silicene composites and operated as an external interfacial layer between Al and different type substrates of p-Si and n-Si to compare Schottky-type photodiodes of PANI–silicene/n-Si and PANI–silicene/p-Si. The silicene structures were investigated using X-ray diffractometry (XRD) and scanning electron microscopy (SEM) techniques. Also, the light power intensity dependent of PANI–silicene/n-Si and PANI–silicene/p-Si photodiodes carried out in the range 0–100 mW/cm² and I–t measurements utilized to determine the response time of the photodiodes. Basic parameters of devices such as ideality factors barrier, height, and series resistance were obtained by Norde and Cheung methods and thermionic emission (TE) theory from I–V graphs. While the PANI–silicene/n-Si exhibited high ideality factor values of 5.49, the PANI–silicene/p-Si photodiodes showed a low ideality factor of 1.48. The photodiode parameters such as detectivity and responsivity were calculated as 6.40 × 10⁹ Jones and 38.9 mA/W for n-Si substrate and 78.2 mA/W and 8.81 × 10⁹ Jones for p-Si substrate. The case of basic electrical properties for PANI–silicene composite interlayer-based photodiodes was analyzed in detail.
... The most widely used semiconductor in optoelectronic applications is silicon with a bandgap of 1.12 eV. Due to its relatively low bandgap, its applications are limited to the visible and near-infrared regions [1][2][3]. Although this disadvantage has been tried to be eliminated by various doping of Si, the resulting production difficulties and high costs have necessitated the development of new types of materials in optoelectronic applications. ...
In this study, V2O5 nanoflakes (NFs) was coated on Si substrate by DC sputtering to obtain V2O5 NFs/n-Si heterojunction. To utilize V2O5 NFs as a broadband photodetector, absorbance spectra were studied using UV−Vis−near-IR spectroscopy. Cut-off wavelength was 530 nm. Furthermore, energy dispersive x-ray, x-ray diffraction (XRD), x-ray photoelectron spectroscopy (XPS) and scanning electron microscope analyses of V2O5 NFs were achieved. The V2O5 NFs/n-Si device gave a very high rectifying ratio of 1.18 × 10⁴ in the dark and at zero bias, it has self-powered mode and an on/off ratio of 1.29 × 10⁶. Optical analyses of the V2O5 NFs/n-Si heterojunction device were studied in detail under UV (365, 395 nm) and IR (850 nm) illumination as well as visible light with varying light intensities. Analysis of experimental studies showed that the device has a high photoresponse under all illuminations. For optical analysis based on I–V measurements, responsivity, detectivity, on/off ratio, external quantum efficiency (EQE), normalized photocurrent-dark-current ratio and noise-equivalent power (NEP) analyses were achieved. The maximum values of responsivity from measurements under visible, UV (395 nm) and IR illumination (850 nm) were 104, 882 and 850 mA W⁻¹ for −2.0 V, respectively. Detectivity values are maximized at V = 0 V and are 6.84 × 10¹¹, 7.87 × 10¹² and 6.87 × 10¹²Jones for the same illuminations respectively. With increasing intensity, the rectification ratio and NEP decreased while the other parameters generally increased. The increase in performance at increasing visible intensity was attributed to the increase in photogenerated carrier density at high intensities, and the high performance in the UV region was attributed to the high light absorption of V2O5 NFs in the UV region.
... The voltage-dependence of the photocurrent is weaker at low light intensities than at high light intensities, but toward high light intensities, the photocurrent is more pronounced than at low intensities. This can be explained by the fact that with increasing light intensity, more photons are absorbed, resulting in more photogenerated carriers, a decrease in recombination current, 62 and an increment in external quantum efficiency (EQE). 63 The ratio of photocurrent to dark current is called the on/off ratio of the photodiode and provides information about the light response level of the optical device. ...
Herein, Ag@ZnO core–shell nanostructures were prepared via the wet chemical method and were then dissolved in methanol and drop cast onto a p–Si wafer. Experimental current–voltage measurements of the Ag@ZnO/p–Si heterojunction device were investigated under both visible and UV illumination of 365 and 395 nm. The photocurrent, responsivity, detectivity, and on/off ratio were found to be dependent on the light intensity of visible light and wavelength of UV light. The low photocurrent at low light intensities and its rapid increase at high light intensities was attributed to the recombination of electrons and holes and also to the presence of traps at low light intensities. The responsivity and detectivity of the photodiode reach 1.32 A/W and 5.47 × 10¹¹ Jones, respectively at 365 nm. On the contrary, the high performance under UV light was explained by the surface plasmon resonance between Ag and ZnO.
... As in every field of technology, low production cost, low power consumption and long-term stability are three of the main factors that make optical devices superior. For low manufacturing cost, suitable materials and manufacturing methods are preferred, while for low power consumption, a self-driven photodetector [8,9] with low parasitic resistances is required. For long-term stability, materials that do not show physical or chemical changes over time or whose changes are almost negligible are preferred. ...
A Hibiscus sabdariffa (HBS)/n-Si hybrid photodetector was fabricated and it was observed that the device has a high rectification ratio of 10.2×104 in dark and superior photoresponse at different intensities of visible light in addition to UV and IR lights. The non-linear response to light intensity in visible light was attributed to phase change effects and the presence of traps, which are the result of the hibiscus sabdariffa' response to light. The responsivity at 850 nm reaches 1.16 A/W (at V= -2.0 V) and a high specific detectivity of 2.0×1012 Jones (for self-driven mode) with an external quantum efficiency of 411% was obtained. In addition, in self-driven mode of UV and IR lights, the highest on/off ratio and NPDR values reached ~105 and ~109 W-1 levels, respectively. Moreover, HBS/n-Si hybrid broad-band photodetector showed long-term stability (40 days) without encapsulation both in the dark and under the light.
The self-powered PVP-Co@C nanofibers/n-GaAs heterojunction photodetector (HJPD) was fabricated by electrospinning of the PVP-Co@C nanofibers onto GaAs. An excellent rectification ratio of 6.60×106 was obtained from I-V measurements of the device in the dark. The I-V measurements of the fabricated device under 365 nm, 395 nm and 850 nm lights, as well as I-V measurements in visible light depending on the light intensity, were performed. The HJPD demonstrated excellent photodetection performance in terms of a good responsivity of ∼ 225 mA/W (at -1.72 V) and at zero bias, an impressive detectivity of 6.28×1012 Jones, and a high on/off ratio of 8.38×105, all at 365 nm wavelength. In addition, the maximum external quantum efficiency and NPDR values were 3495% (V=-1.72 V) and 2.60×1010 W-1 (V=0.0 V), respectively, while the minimum NEP value was ∼10-14 W.Hz-1/2 for 365 nm at V=0.V volts. The HJPD also exhibited good long-term stability in air after 30 days without any encapsulation.
