4 results
Search Results
Now showing 1 - 4 of 4
Article Citation - WoS: 19Citation - Scopus: 19A Study on the Dark and Illuminated Operation of Al/Si3< Schottky Photodiodes: Optoelectronic Insights(Springer Heidelberg, 2024) Surucu, Ozge; Yildiz, Dilber Esra; Yildirim, MuratThis work extensively investigates the operation of an Al/ Si3N4/p-Si Schottky-type photodiode under dark and varying illumination intensities. The photodiode is fabricated by employing the metal-organic chemical vapor deposition (MOCVD) method. A thorough electrical characterization is performed at room temperature, encompassing measurements of current-voltage (I-V), current-time (I-t), capacitance-time (C-t), and conductance time (G-t). The photodiode's rectification factor and reverse bias area increased under illumination. The relationship between light power density, barrier height, and diode ideality factor is found. The study also found a strong correlation between light intensity and applied voltage on series resistance (R-s) and shunt resistance (R-sh). R-s values are calculated using Cheung's functions, revealing the diode's resistance behavior. The study also examines the photodiode's photoconductivity and photoconductance, finding a non-linear relationship between photocurrent and illumination intensity, suggesting bimolecular recombination. Calculated photosensitivity (K), responsivity (R), and detectivity (D*) values show the device's light response effectiveness, but efficiency decreases at higher illumination intensities. Transient experiments indicate stable and reproducible photocurrent characteristics, revealing photogenerated charge temporal evolution. This study provides a complete understanding of the Al/Si3N4/p-Si Schottky photodiode's behavior under different illumination intensities. The findings advance optoelectronic device knowledge and enable their use in advanced technologies.Article Citation - WoS: 2Role of Au Nanosheets in Enhancing the Performance of Yb/Zns Tunneling Photosensors(Natl inst R&d Materials Physics, 2020) Abusaa, M.; Qasrawi, A. F.; Assad, B. M.; Khanfar, H. K.In this study, the effects of Au nanosheets of thicknesses of 50 nm on the structural, electrical and photoelectrical properties of Yb/ZnS/CdS/Au (ZAC-0) devices is considered. Stacked layers of ZnS and CdS which are prepared by the thermal evaporation technique onto Yb substrates under vacuum pressure of 10(-5) mbar exhibits rectifying characteristics. For these diodes a reverse to forward current ratios of similar to 10(5) at biasing voltage of 0.60 V is determined. Insertion of Au nanosheets between the stacked layers of ZnS and CdS increased the current values by three orders of magnitude and changed the current conduction mechanism from thermionic emission to tunneling under reverse biasing conditions. The ZAC-0 device, exhibit a barrier height lowering and barrier widening upon insertion of Au nanosheets. After the participation of Au nanosheets in the structure of the ZAC-0 devices, large photosensitivity and responsivity accompanied with high external quantum efficiency is observed. The responsivity to 406 nm laser radiation is biasing voltage dependent and reaches 135 mA/W at 0.60 V. The features of the Yb/ZnS/Au/CdS/Au photosensors nominate them as promising candidates for use in light communication technology as signal receivers.Article Citation - WoS: 77Citation - Scopus: 78Electrical Properties of Al/Pcbm:zno Heterojunction for Photodiode Application(Elsevier Science Sa, 2020) Gullu, H. H.; Yildiz, D. E.; Kocyigit, A.; Yildirim, M.In this paper, the electrical characteristics of spin-coated PCBM:ZnO interlayered Al/PCBM:ZnO/Si diode are investigated under the aim of photodiode application. Under dark condition, the diode shows about four orders in magnitude rectification rate and diode illumination results in efficient rectification with increase in intensity. The analysis of current-voltage curve results a non-ideal diode characteristics according to the thermionic emission model due to the existence of parasitic resistances and interface states. The measured current-voltage values are used to extract the barrier height and ideality factor under dark and illumination conditions. Under illumination, photo-generated carriers contribute to the current flow and linear photo-conductivity behavior in photo-current measurements with illumination shows the possible use of hybrid PCBM:ZnO layer in Si-based photodiodes. In addition, change in the series and shunt resistance values under illumination is found to be effective in this light-sensing behavior of the diode. This characteristic is also observed from the typical on/off illumination switching behavior for the photodiodes in transient photo-current, photo-capacitance and photo-conductance measurements with the quick response to the illumination. The deviations from ideality are also discussed by means of distribution of interface states and series resistance depending on the applied frequency and bias voltage. (C) 2020 Elsevier B.V. All rights reserved.Article Citation - Scopus: 2Role of au nanosheets in enhancing the performance of yb/zns/cds/au tunneling photosensors(S.C. Virtual Company of Phisics S.R.L, 2020) Abusaa,M.; Qasrawi,A.F.; Asaad,B.M.; Khanfar,H.K.In this study, the effects of Au nanosheets of thicknesses of 50 nm on the structural, electrical and photoelectrical properties of Yb/ZnS/CdS/Au (ZAC-0) devices is considered. Stacked layers of ZnS and CdS which are prepared by the thermal evaporation technique onto Yb substrates under vacuum pressure of 10-5 mbar exhibits rectifying characteristics. For these diodes a reverse to forward current ratios of ~105 at biasing voltage of 0.60 V is determined. Insertion of Au nanosheets between the stacked layers of ZnS and CdS increased the current values by three orders of magnitude and changed the current conduction mechanism from thermionic emission to tunneling under reverse biasing conditions. The ZAC-0 device, exhibit a barrier height lowering and barrier widening upon insertion of Au nanosheets. After the participation of Au nanosheets in the structure of the ZAC-0 devices, large photosensitivity and responsivity accompanied with high external quantum efficiency is observed. The responsivity to 406 nm laser radiation is biasing voltage dependent and reaches 135 mA/W at 0.60 V. The features of the Yb/ZnS/Au/CdS/Au photosensors nominate them as promising candidates for use in light communication technology as signal receivers. © 2020, S.C. Virtual Company of Phisics S.R.L. All rights reserved.
