The Experts below are selected from a list of 18789 Experts worldwide ranked by ideXlab platform
M A Yeganeh - One of the best experts on this subject based on the ideXlab platform.
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studying of barrier height and Ideality Factor relation in the nano sized au n type si schottky diodes
Superlattices and Microstructures, 2011Co-Authors: M A Yeganeh, R Mamedov, Sh RahmatallahpurAbstract:Abstract The results of formation of the operating potential barrier height (Φв) of inhomogeneous Schottky diodes (SD) in view of an additional electric field in the near contact region of the semiconductor and features of its dependence on the external applied voltage are presented. A correlation, between SD heterogeneity and dependence between potential barrier height (Φв) and Ideality Factor (n), is presented. Using conducting probe atomic force microscope (CP-AFM) techniques, it is shown that Au/n-Si diodes consist of sets of parallel-connected and cooperating nano diodes with the contact surfaces sizes in the order of 100–200 nm. The effective Φв and Ideality Factors of the SD have been obtained from the current–voltage (I–V) characteristics, which were measured using a CP-AFM along a contact surface. It was experimentally shown that the forward and reverse part of I–V characteristics and their effective Φв and Ideality Factors of the identically fabricated nano-SD differ from diode to diode. The Φв for the nano-SD has ranged from 0.565 to 0.723 eV and Ideality Factor from 1.11 to 1.98. No correlation can be found between the Φв and Ideality Factor. The Φв distribution obtained from the I–V characteristics has been fitted by a Gaussian function but the Ideality Factor distribution could not be fitted by a Gaussian function.
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effect of diode size and series resistance on barrier height and Ideality Factor in nearly ideal au n type gaas micro schottky contact diodes
Chinese Physics B, 2010Co-Authors: M A Yeganeh, Sh Rahmatallahpur, A Nozad, R MamedovAbstract:Small high-quality Au/n type-GaAs Schottky barrier diodes (SBDs) with low reverse leakage current are produced using lithography. Their effective barrier heights (BHs) and Ideality Factors from current-voltage (I–V) characteristics are measured by a Pico ampere meter and home-built I–V instrument. In spite of the identical preparation of the diodes there is a diode-to-diode variation in Ideality Factor and barrier height parameters. Measurement of topology of a surface of a thin metal film with atomic force microscope (AFM) shows that Au-n type-GaAS SD consists of a set of parallel-connected micro and nanocontacts diodes with sizes approximately in a range of 100–200 nm. Between barrier height and Ideality Factor there is an inversely proportional dependency. With the diameter of contact increasing from 5 μm up to 200 μm, the barrier height increases from 0.833 up to 0.933 eV and its Ideality Factor decreases from 1.11 down to 1.006. These dependencies show the reduction of the contribution of the peripheral current with the diameter of contact increasing. We find the effect of series resistance on barrier height and Ideality Factor.
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dependency of barrier height and Ideality Factor on identically produced small au p si schottky barrier diodes
Physica B-condensed Matter, 2010Co-Authors: M A Yeganeh, Sh Rahmatollahpur, R Sadighibonabi, R MamedovAbstract:Abstract Small high-quality Au/p-Si Schottky barrier diodes (SBDs) with extremely low reverse leakage current using wet lithography were produced. Their effective barrier heights (BHs) and Ideality Factors from current–voltage ( I – V ) characteristics were measured by a conducting probe atomic force microscope (C-AFM). In spite of identical preparation of the diodes there was a diode-to-diode variation in Ideality Factor and barrier height parameters. By extrapolating the plots the built-in potential of the Au/p-Si contact was obtained as V bi = 0.5425 V and the barrier height value ( Φ B ( C − V ) ) was calculated to be Φ B ( C − V ) =0.7145 V for Au/p-Si for a typical 100 μm diode diameters. In the present work the nonlinear dependency of BH and Ideality Factor on the diode diameter studied fundamentally and an experimental relation for this new behavior is derived. It is found that for the diodes with diameters smaller than 100 μm the diode barrier height and Ideality Factor dependency to their diameters and correlation between the diode barrier height and its Ideality Factor are nonlinear, which is similar to the earlier reported different metal semiconductor diodes in the literature, these parameters for the here manufactured diodes with diameters more than 100 μm are also linear. Based on the very obvious sub-nanometer C-AFM produced pictures, the scientific evidence behind this controversy is also explained.
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barrier height and Ideality Factor dependency on identically produced small au p si schottky barrier diodes
Journal of Semiconductors, 2010Co-Authors: M A Yeganeh, Sh RahmatollahpurAbstract:Small high-quality Au/P-Si Schottky barrier diodes (SBDs) with an extremely low reverse leakage current using wet lithography were produced. Their effective barrier heights (BHs) and Ideality Factors from current-voltage (I–V) characteristics were measured by a conducting probe atomic force microscope (C-AFM). In spite of the identical preparation of the diodes there was a diode-to-diode variation in Ideality Factor and barrier height parameters. By extrapolating the plots the built in potential of the Au/p-Si contact was obtained as Vbi = 0.5425 V and the barrier height value ΦB(C-V) was calculated to be ΦB(C-V) = 0.7145 V for Au/p-Si. It is found that for the diodes with diameters smaller than 100 μm, the diode barrier height and Ideality Factor dependency to their diameters and correlation between the diode barrier height and its Ideality Factor are nonlinear, where similar to the earlier reported different metal semiconductor diodes in the literature, these parameters for the here manufactured diodes with diameters more than 100 μm are also linear. Based on the very obvious sub-nanometer C-AFM produced pictures the scientific evidence behind this controversy is also explained.
Siva Sivoththaman - One of the best experts on this subject based on the ideXlab platform.
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near unity Ideality Factor diodes using nanocrystalline si multicrystalline si heterojunctions for photovoltaic application
Journal of Vacuum Science and Technology, 2006Co-Authors: Mahdi Farrokhbaroughi, Siva SivoththamanAbstract:High-quality heterojunction diodes with near-unity Ideality Factor were fabricated by direct deposition of a (n+) nanocrystalline silicon film on top of fine-grained (p) multicrystalline silicon substrates. A very good Ideality Factor of 1.08 was achieved using a single-diode model in the medium forward-bias regime. Current-voltage (IV) characteristics of the diodes measured in the dark show that the recombination at the heterointerface is much less than the recombination at the space-charge region in the low forward-bias regime confirming the fact that the junction quality is good and is suitable for photovoltaic applications. Internal quantum efficiency measurements performed on these cells show a high (>70%) blue response partly due to a high transparency of the n+ nanocrystalline material. Illuminated IV of the heterojunction solar cells show a high fill Factor of 78%–79% and an acceptable open circuit voltage of 550mV for a simple structure without a rear-surface passivation or transparent conductive...
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Near-unity Ideality Factor diodes using nanocrystalline Si/multicrystalline Si heterojunctions for photovoltaic application
Journal of Vacuum Science & Technology A, 2006Co-Authors: Mahdi Farrokh Baroughi, C.-h. Lee, Siva SivoththamanAbstract:High-quality heterojunction diodes with near-unity Ideality Factor were fabricated by direct deposition of a (n(+)) nanocrystalline silicon film on top of fine-grained (p) multicrystalline silicon substrates. A very good Ideality Factor of 1.08 was achieved using a single-diode model in the medium forward-bias regime. Current-voltage (IV) characteristics of the diodes measured in the dark show that the recombination at the heterointerface is much less than the recombination at the space-charge region in the low forward-bias regime confirming the fact that the junction quality is good and is suitable for photovoltaic applications. Internal quantum efficiency measurements performed on these cells show a high (> 70%) blue response partly due to a high transparency of the n(+) nanocrystalline material. Illuminated IV of the heterojunction solar cells show a high fill Factor of 78% - 79% and an acceptable open circuit voltage of 550 mV for a simple structure without a rear-surface passivation or transparent conductive oxide. (c) 2006 American Vacuum Society.
J.s. Harris - One of the best experts on this subject based on the ideXlab platform.
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diode Ideality Factor for surface recombination current in algaas gaas heterojunction bipolar transistors
IEEE Transactions on Electron Devices, 1992Co-Authors: J.s. HarrisAbstract:n-p-n AlGaAs/GaAs heterojunction bipolar transistors of various emitter areas have been fabricated to examine the diode Ideality Factor for surface recombination. These transistors are fabricated with and without exposed extrinsic base surfaces. Comparison of the measured results indicates that the base surface recombination current increases exponentially with the base-emitter voltage with an Ideality Factor which is closer to 1 than 2(1 >
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Diode Ideality Factor for surface recombination current in AlGaAs/GaAs heterojunction bipolar transistors
IEEE Transactions on Electron Devices, 1992Co-Authors: J.s. HarrisAbstract:n-p-n AlGaAs/GaAs heterojunction bipolar transistors of various emitter areas have been fabricated to examine the diode Ideality Factor for surface recombination. These transistors are fabricated with and without exposed extrinsic base surfaces. Comparison of the measured results indicates that the base surface recombination current increases exponentially with the base-emitter voltage with an Ideality Factor which is closer to 1 than 2(1
R Mamedov - One of the best experts on this subject based on the ideXlab platform.
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studying of barrier height and Ideality Factor relation in the nano sized au n type si schottky diodes
Superlattices and Microstructures, 2011Co-Authors: M A Yeganeh, R Mamedov, Sh RahmatallahpurAbstract:Abstract The results of formation of the operating potential barrier height (Φв) of inhomogeneous Schottky diodes (SD) in view of an additional electric field in the near contact region of the semiconductor and features of its dependence on the external applied voltage are presented. A correlation, between SD heterogeneity and dependence between potential barrier height (Φв) and Ideality Factor (n), is presented. Using conducting probe atomic force microscope (CP-AFM) techniques, it is shown that Au/n-Si diodes consist of sets of parallel-connected and cooperating nano diodes with the contact surfaces sizes in the order of 100–200 nm. The effective Φв and Ideality Factors of the SD have been obtained from the current–voltage (I–V) characteristics, which were measured using a CP-AFM along a contact surface. It was experimentally shown that the forward and reverse part of I–V characteristics and their effective Φв and Ideality Factors of the identically fabricated nano-SD differ from diode to diode. The Φв for the nano-SD has ranged from 0.565 to 0.723 eV and Ideality Factor from 1.11 to 1.98. No correlation can be found between the Φв and Ideality Factor. The Φв distribution obtained from the I–V characteristics has been fitted by a Gaussian function but the Ideality Factor distribution could not be fitted by a Gaussian function.
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effect of diode size and series resistance on barrier height and Ideality Factor in nearly ideal au n type gaas micro schottky contact diodes
Chinese Physics B, 2010Co-Authors: M A Yeganeh, Sh Rahmatallahpur, A Nozad, R MamedovAbstract:Small high-quality Au/n type-GaAs Schottky barrier diodes (SBDs) with low reverse leakage current are produced using lithography. Their effective barrier heights (BHs) and Ideality Factors from current-voltage (I–V) characteristics are measured by a Pico ampere meter and home-built I–V instrument. In spite of the identical preparation of the diodes there is a diode-to-diode variation in Ideality Factor and barrier height parameters. Measurement of topology of a surface of a thin metal film with atomic force microscope (AFM) shows that Au-n type-GaAS SD consists of a set of parallel-connected micro and nanocontacts diodes with sizes approximately in a range of 100–200 nm. Between barrier height and Ideality Factor there is an inversely proportional dependency. With the diameter of contact increasing from 5 μm up to 200 μm, the barrier height increases from 0.833 up to 0.933 eV and its Ideality Factor decreases from 1.11 down to 1.006. These dependencies show the reduction of the contribution of the peripheral current with the diameter of contact increasing. We find the effect of series resistance on barrier height and Ideality Factor.
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dependency of barrier height and Ideality Factor on identically produced small au p si schottky barrier diodes
Physica B-condensed Matter, 2010Co-Authors: M A Yeganeh, Sh Rahmatollahpur, R Sadighibonabi, R MamedovAbstract:Abstract Small high-quality Au/p-Si Schottky barrier diodes (SBDs) with extremely low reverse leakage current using wet lithography were produced. Their effective barrier heights (BHs) and Ideality Factors from current–voltage ( I – V ) characteristics were measured by a conducting probe atomic force microscope (C-AFM). In spite of identical preparation of the diodes there was a diode-to-diode variation in Ideality Factor and barrier height parameters. By extrapolating the plots the built-in potential of the Au/p-Si contact was obtained as V bi = 0.5425 V and the barrier height value ( Φ B ( C − V ) ) was calculated to be Φ B ( C − V ) =0.7145 V for Au/p-Si for a typical 100 μm diode diameters. In the present work the nonlinear dependency of BH and Ideality Factor on the diode diameter studied fundamentally and an experimental relation for this new behavior is derived. It is found that for the diodes with diameters smaller than 100 μm the diode barrier height and Ideality Factor dependency to their diameters and correlation between the diode barrier height and its Ideality Factor are nonlinear, which is similar to the earlier reported different metal semiconductor diodes in the literature, these parameters for the here manufactured diodes with diameters more than 100 μm are also linear. Based on the very obvious sub-nanometer C-AFM produced pictures, the scientific evidence behind this controversy is also explained.
Sh Rahmatallahpur - One of the best experts on this subject based on the ideXlab platform.
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studying of barrier height and Ideality Factor relation in the nano sized au n type si schottky diodes
Superlattices and Microstructures, 2011Co-Authors: M A Yeganeh, R Mamedov, Sh RahmatallahpurAbstract:Abstract The results of formation of the operating potential barrier height (Φв) of inhomogeneous Schottky diodes (SD) in view of an additional electric field in the near contact region of the semiconductor and features of its dependence on the external applied voltage are presented. A correlation, between SD heterogeneity and dependence between potential barrier height (Φв) and Ideality Factor (n), is presented. Using conducting probe atomic force microscope (CP-AFM) techniques, it is shown that Au/n-Si diodes consist of sets of parallel-connected and cooperating nano diodes with the contact surfaces sizes in the order of 100–200 nm. The effective Φв and Ideality Factors of the SD have been obtained from the current–voltage (I–V) characteristics, which were measured using a CP-AFM along a contact surface. It was experimentally shown that the forward and reverse part of I–V characteristics and their effective Φв and Ideality Factors of the identically fabricated nano-SD differ from diode to diode. The Φв for the nano-SD has ranged from 0.565 to 0.723 eV and Ideality Factor from 1.11 to 1.98. No correlation can be found between the Φв and Ideality Factor. The Φв distribution obtained from the I–V characteristics has been fitted by a Gaussian function but the Ideality Factor distribution could not be fitted by a Gaussian function.
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effect of diode size and series resistance on barrier height and Ideality Factor in nearly ideal au n type gaas micro schottky contact diodes
Chinese Physics B, 2010Co-Authors: M A Yeganeh, Sh Rahmatallahpur, A Nozad, R MamedovAbstract:Small high-quality Au/n type-GaAs Schottky barrier diodes (SBDs) with low reverse leakage current are produced using lithography. Their effective barrier heights (BHs) and Ideality Factors from current-voltage (I–V) characteristics are measured by a Pico ampere meter and home-built I–V instrument. In spite of the identical preparation of the diodes there is a diode-to-diode variation in Ideality Factor and barrier height parameters. Measurement of topology of a surface of a thin metal film with atomic force microscope (AFM) shows that Au-n type-GaAS SD consists of a set of parallel-connected micro and nanocontacts diodes with sizes approximately in a range of 100–200 nm. Between barrier height and Ideality Factor there is an inversely proportional dependency. With the diameter of contact increasing from 5 μm up to 200 μm, the barrier height increases from 0.833 up to 0.933 eV and its Ideality Factor decreases from 1.11 down to 1.006. These dependencies show the reduction of the contribution of the peripheral current with the diameter of contact increasing. We find the effect of series resistance on barrier height and Ideality Factor.