Dr David Etor | University of Jos (original) (raw)

Papers by Dr David Etor

FUOYE Journal of Engineering and Technology

The fabrication of metal–insulator– metal (MIM) diode using an ultrathin Al2O3 insulator layer, d... more The fabrication of metal–insulator– metal (MIM) diode using an ultrathin Al2O3 insulator layer, deposited using atomic layer deposition (ALD) is presented. The Al2O3 insulating layer was found to be highly uniform throughout the diode junction, effectively overcoming the main fabrication challenge in MIM diodes. The diodes exhibit strong non-linear current–voltage curves, have a typical zero-bias curvature coefficient of 5.4 V−1 and a zero-bias resistance of approximately 118 kΩ, a value considerably smaller than other MIM diode topologies and that allows more current to be rectified. Other results including current ratio and yield of the diode also competes favorably with the state-of-the-art MIM diodes such as the recently produced metal-octadecyltrichlorosilane (OTS)-metal structure.

AIP Advances, 2019

The full-text may be used and/or reproduced, and given to third parties in any format or medium, ... more The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.

2016 41st International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz), 2016

An effective impedance matching technique for rectennas (an antenna coupled with rectifier) opera... more An effective impedance matching technique for rectennas (an antenna coupled with rectifier) operating at specific frequencies is presented. The rectifier consists of an MIM junction with a molecular insulator. The method used two coplanar strip lines emerging from the antenna feed-point, to correct for the reactive component of the antenna impedance on one side, and to connect the rectifier and transform its impedance on the other side. Microwave and mm-wave characterization of the devices showed that the responsivity of the impedance matched rectenna is almost an order of magnitude higher than that of a control device without matching network at 20 GHz.

2016 41st International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz), 2016

The fabrication and testing of metal-insulatormetal (MIM) diodes on a flexible substrate for micr... more The fabrication and testing of metal-insulatormetal (MIM) diodes on a flexible substrate for microwave and mm-wave applications are presented. The diodes utilized octadecyltrichlorosilane (OTS), which self assembles and provide a thin, pin holes free insulator. Preliminary electrical analysis shows that the diodes have a typical zero bias resistance of approximately 80 kΩ, zero-bias curvature coefficient (γ_ZB) of approximately 5.5 V-1 , and voltage responsivity of 3.1 kV/W at a frequency of 1 GHz, and are produced with over 90% device yield. The fabrication process is simple and cost effective, environmentally friendly, and demonstrates the possibility of roll-to-roll volume manufacturing of MIM diodes.

2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz), 2015

The fabrication of low-cost metal-insulator-metal (MIM) diodes using a self-assembled monolayer a... more The fabrication of low-cost metal-insulator-metal (MIM) diodes using a self-assembled monolayer as the insulating layer is presented. DC and AC analysis show that the diodes have excellent non-linear current voltage characteristics compared to those typically reported, with a zero-bias curvature coefficient ranging from 0.5 V-1 to 5.4 V-1, voltage responsivity of 1.9 kV/W at a frequency of 1 GHz. The process developed for fabricating these diodes is simple, cost effective, and can potentially be used in the roll-to-roll manufacturing of MIM diodes. Reliability tests performed on the fabricated OTS diodes shows that the OTS layer of the diodes remains unaffected by high temperature up to approximately 450 °C which is significant in thermal energy harvesting applications, where the diode may be exposed to high temperatures.

2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz), 2015

A simple and elegant method for matching the impedance of a typical THz self-complementary bowtie... more A simple and elegant method for matching the impedance of a typical THz self-complementary bowtie antenna to the high-impedance of a nanodiode is proposed. Two twin-lead balanced lines emerging from the antenna feed-point are used to connect the diode, correct for the reactive component of the antenna impedance and compensate the parasitic capacitance of the diode. Numerical simulations considering a model rectenna with a metal-insulator-metal diode showed that impedances up to several kΩ can be effectively matched.

2015 1st URSI Atlantic Radio Science Conference (URSI AT-RASC), 2015

This work presents the fabrication of novel high-frequency low-cost metal-insulator-metal (MIM) d... more This work presents the fabrication of novel high-frequency low-cost metal-insulator-metal (MIM) diodes with the dielectric (insulating) layer formed using a chemical approach at low temperature, rather than using the more aggressive techniques typical of the semiconductor industry. This device is a useful component in a wide range of applications, including radio frequency identification (RFID), high frequency detectors and mixers, and electromagnetic energy harvesting as in (Y. Pan, C. V. Powell, A. M. Song, and C. Balocco, “Micro Rectennas: Brownian Ratchets for Thermal-Energy Harvesting”, Appl. Phys. Lett. 105, 253901, 2014).

IEEE Transactions on Electron Devices, 2016

The design and fabrication metal-insulator-metal (MIM) diodes using an ultra-thin organic insulat... more The design and fabrication metal-insulator-metal (MIM) diodes using an ultra-thin organic insulator is presented. The insulating layer was found to be compact, highly conformal, and uniform, effectively overcoming the main design challenge in MIM diodes. The diodes have strong non-linear current-voltage characteristics with a typical zero-bias curvature coefficient 5.4 V-1 and a voltage responsivity of 1.9 kV/W at a frequency of 1 GHz. The fabrication of the diodes only requires lowtemperature processing, is cost effective, and can potentially be ported to large-area roll-to-roll manufacturing.

The work in this thesis investigates the design and fabrication of metal-insulator-metal (MIM) di... more The work in this thesis investigates the design and fabrication of metal-insulator-metal (MIM) diodes using an ultrathin organic insulator. The organic insulating layer was found to be compact, highly conformal, and uniform, effectively overcoming the main design challenge in MIM diodes. The fabricated diodes have strong nonlinear current-voltage characteristics with a zero-bias curvature coefficient and a voltage responsivity among the best values reported in the available literature. The fabrication process is simple and carried out at low temperature, which is cost effective, and can potentially be ported to large-area roll-to-roll manufacturing. An encapsulation method to prevent MIM junctions’ degradation has also been developed. Following the successful production of these MIM devices on a rigid substrate, with the fabrication only requiring low-temperature processing, the diodes were successfully fabricated on a flexible substrate with results similar to those fabricated on a...

A simple and elegant method impedance of a typical THz self-complementar to the high-impedance of... more A simple and elegant method impedance of a typical THz self-complementar to the high-impedance of a nanodiode is propos balanced lines emerging from the antenna feed connect the diode, correct for the reactive c antenna impedance and compensate the parasi the diode. Numerical simulations considering with a metal-insulator-metal diode showed that several kΩ can be effectively matched.

Applied Physics Letters, 2016

We report on the fabrication and testing of metal-insulator-metal (MIM) diodes on a flexible subs... more We report on the fabrication and testing of metal-insulator-metal (MIM) diodes on a flexible substrate where the thin insulating layer self-assembles as a monolayer sandwiched between the two metal electrodes. The current-voltage characteristic has a strong asymmetry and non-linearity at zero-bias.

AIP Advances, 2019

This paper reports on the experimental investigation of metal-insulator-metal (MIM) diodes based... more This paper reports on the experimental investigation of metal-insulator-metal (MIM) diodes based on alkyltrichlorosilane self-assembled monolayers (SAMs) with different alkyl chain lengths. The insulating SAM is sandwiched between two metal contacts, Pt and Ti, with different work functions. The electronic properties of the MIM diodes can be tuned by controlling the alkyl chain length of the SAMs to address different constraints in high speed electronics applications. Data fitting of the tunneling current through the MIM junctions using the Fowler-Nordheim model suggests that the device operation is influenced by the barrier heights of the diodes and thicknesses of the SAMs. The current-voltage characteristics achieved in MIM diodes based on alkyltrichlorosilane SAMs make them promising candidates for high speed electronics applications.

The model of a hybrid dc-dc boost converter, which consists of the conventional and a 2-phase int... more The model of a hybrid dc-dc boost converter, which consists of the conventional and a 2-phase interleaved dcdc boost converters, is reported. The efficiency of the hybrid converter is well above 90% and remains so throughout the operating period of the system. The model is simple and compact, and will be very useful in applications where a roundthe-clock high efficiency performance is of paramount importance.

The fabrication of low-cost met (MIM) diodes using a self-assembled mo insulating layer is presen... more The fabrication of low-cost met (MIM) diodes using a self-assembled mo insulating layer is presented. DC and AC analy diodes have excellent non-linear current volta compared to those typically reported, with a ze coefficient ranging from 0.5 V -1 to 5.4 V -1 , volta 1.9 kV/W at a frequency of 1 GHz. The proc fabricating these diodes is simple, cost ef potentially be used in the roll-to-roll manuf diodes. Reliability tests performed on the fabri shows that the OTS layer of the diodes rema high temperature up to approximately 450 °C w in thermal energy harvesting applications, whe be exposed to high temperatures.

An effective impedance matching technique for rectennas (an antenna coupled with rectifier) opera... more An effective impedance matching technique for rectennas (an antenna coupled with rectifier) operating at specific frequencies is presented. The rectifier consists of a MIM junction with a molecular insulator. The method used two coplanar strip lines emerging from the antenna feed-point, to correct for the reactive component of the antenna impedance on one side, and to connect the rectifier and transform its impedance on the other side. Microwave and mm-wave characterization of the devices showed that the output voltage of the impedance matched rectenna is almost an order of magnitude higher than that of a control device without matching network at 20 GHz.

A simple and elegant method impedance of a typical THz self-complementar to the high-impedance of... more A simple and elegant method impedance of a typical THz self-complementar to the high-impedance of a nanodiode is propos balanced lines emerging from the antenna feed connect the diode, correct for the reactive c antenna impedance and compensate the parasi the diode. Numerical simulations considering with a metal-insulator-metal diode showed that several k can be effectively matched.

The fabrication and testing of metal-insulatormetal (MIM) diodes on a flexible substrate for micr... more The fabrication and testing of metal-insulatormetal (MIM) diodes on a flexible substrate for microwave and mm-wave applications are presented. The diodes utilized octadecyltrichlorosilane (OTS), which self assembles to form a thin, pin holes free insulator. Preliminary electrical analysis shows that the diodes have a typical zero bias resistance of approximately 80 k , zero-bias curvature coefficient ( _ZB) of approximately 5.5 V -1 , and voltage responsivity of 3.1 kV/W at a frequency of 1 GHz, and are produced with over 90% device yield. The fabrication process is simple and cost effective, environmentally friendly, and demonstrates the possibility of roll-to-roll volume manufacturing of MIM diodes.

This work presents the fabrication of novel high-frequency low-cost metal-insulator-metal (MIM) d... more This work presents the fabrication of novel high-frequency low-cost metal-insulator-metal (MIM) diodes with the dielectric (insulating) layer formed using a chemical approach at low temperature, rather than using the more aggressive techniques typical of the semiconductor industry. This device is a useful component in a wide range of applications, including radio frequency identification (RFID), high frequency detectors and mixers, and electromagnetic energy harvesting as in (Y. Pan, C. V. Powell, A. M. Song, and C. Balocco, "Micro Rectennas: Brownian Ratchets for Thermal-Energy Harvesting", Appl. Phys. Lett. 105, 253901, 2014).

FUOYE Journal of Engineering and Technology

The fabrication of metal–insulator– metal (MIM) diode using an ultrathin Al2O3 insulator layer, d... more The fabrication of metal–insulator– metal (MIM) diode using an ultrathin Al2O3 insulator layer, deposited using atomic layer deposition (ALD) is presented. The Al2O3 insulating layer was found to be highly uniform throughout the diode junction, effectively overcoming the main fabrication challenge in MIM diodes. The diodes exhibit strong non-linear current–voltage curves, have a typical zero-bias curvature coefficient of 5.4 V−1 and a zero-bias resistance of approximately 118 kΩ, a value considerably smaller than other MIM diode topologies and that allows more current to be rectified. Other results including current ratio and yield of the diode also competes favorably with the state-of-the-art MIM diodes such as the recently produced metal-octadecyltrichlorosilane (OTS)-metal structure.

AIP Advances, 2019

The full-text may be used and/or reproduced, and given to third parties in any format or medium, ... more The full-text may be used and/or reproduced, and given to third parties in any format or medium, without prior permission or charge, for personal research or study, educational, or not-for-prot purposes provided that: • a full bibliographic reference is made to the original source • a link is made to the metadata record in DRO • the full-text is not changed in any way The full-text must not be sold in any format or medium without the formal permission of the copyright holders.

2016 41st International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz), 2016

An effective impedance matching technique for rectennas (an antenna coupled with rectifier) opera... more An effective impedance matching technique for rectennas (an antenna coupled with rectifier) operating at specific frequencies is presented. The rectifier consists of an MIM junction with a molecular insulator. The method used two coplanar strip lines emerging from the antenna feed-point, to correct for the reactive component of the antenna impedance on one side, and to connect the rectifier and transform its impedance on the other side. Microwave and mm-wave characterization of the devices showed that the responsivity of the impedance matched rectenna is almost an order of magnitude higher than that of a control device without matching network at 20 GHz.

2016 41st International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz), 2016

The fabrication and testing of metal-insulatormetal (MIM) diodes on a flexible substrate for micr... more The fabrication and testing of metal-insulatormetal (MIM) diodes on a flexible substrate for microwave and mm-wave applications are presented. The diodes utilized octadecyltrichlorosilane (OTS), which self assembles and provide a thin, pin holes free insulator. Preliminary electrical analysis shows that the diodes have a typical zero bias resistance of approximately 80 kΩ, zero-bias curvature coefficient (γ_ZB) of approximately 5.5 V-1 , and voltage responsivity of 3.1 kV/W at a frequency of 1 GHz, and are produced with over 90% device yield. The fabrication process is simple and cost effective, environmentally friendly, and demonstrates the possibility of roll-to-roll volume manufacturing of MIM diodes.

2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz), 2015

The fabrication of low-cost metal-insulator-metal (MIM) diodes using a self-assembled monolayer a... more The fabrication of low-cost metal-insulator-metal (MIM) diodes using a self-assembled monolayer as the insulating layer is presented. DC and AC analysis show that the diodes have excellent non-linear current voltage characteristics compared to those typically reported, with a zero-bias curvature coefficient ranging from 0.5 V-1 to 5.4 V-1, voltage responsivity of 1.9 kV/W at a frequency of 1 GHz. The process developed for fabricating these diodes is simple, cost effective, and can potentially be used in the roll-to-roll manufacturing of MIM diodes. Reliability tests performed on the fabricated OTS diodes shows that the OTS layer of the diodes remains unaffected by high temperature up to approximately 450 °C which is significant in thermal energy harvesting applications, where the diode may be exposed to high temperatures.

2015 40th International Conference on Infrared, Millimeter, and Terahertz waves (IRMMW-THz), 2015

A simple and elegant method for matching the impedance of a typical THz self-complementary bowtie... more A simple and elegant method for matching the impedance of a typical THz self-complementary bowtie antenna to the high-impedance of a nanodiode is proposed. Two twin-lead balanced lines emerging from the antenna feed-point are used to connect the diode, correct for the reactive component of the antenna impedance and compensate the parasitic capacitance of the diode. Numerical simulations considering a model rectenna with a metal-insulator-metal diode showed that impedances up to several kΩ can be effectively matched.

2015 1st URSI Atlantic Radio Science Conference (URSI AT-RASC), 2015

This work presents the fabrication of novel high-frequency low-cost metal-insulator-metal (MIM) d... more This work presents the fabrication of novel high-frequency low-cost metal-insulator-metal (MIM) diodes with the dielectric (insulating) layer formed using a chemical approach at low temperature, rather than using the more aggressive techniques typical of the semiconductor industry. This device is a useful component in a wide range of applications, including radio frequency identification (RFID), high frequency detectors and mixers, and electromagnetic energy harvesting as in (Y. Pan, C. V. Powell, A. M. Song, and C. Balocco, “Micro Rectennas: Brownian Ratchets for Thermal-Energy Harvesting”, Appl. Phys. Lett. 105, 253901, 2014).

IEEE Transactions on Electron Devices, 2016

The design and fabrication metal-insulator-metal (MIM) diodes using an ultra-thin organic insulat... more The design and fabrication metal-insulator-metal (MIM) diodes using an ultra-thin organic insulator is presented. The insulating layer was found to be compact, highly conformal, and uniform, effectively overcoming the main design challenge in MIM diodes. The diodes have strong non-linear current-voltage characteristics with a typical zero-bias curvature coefficient 5.4 V-1 and a voltage responsivity of 1.9 kV/W at a frequency of 1 GHz. The fabrication of the diodes only requires lowtemperature processing, is cost effective, and can potentially be ported to large-area roll-to-roll manufacturing.

The work in this thesis investigates the design and fabrication of metal-insulator-metal (MIM) di... more The work in this thesis investigates the design and fabrication of metal-insulator-metal (MIM) diodes using an ultrathin organic insulator. The organic insulating layer was found to be compact, highly conformal, and uniform, effectively overcoming the main design challenge in MIM diodes. The fabricated diodes have strong nonlinear current-voltage characteristics with a zero-bias curvature coefficient and a voltage responsivity among the best values reported in the available literature. The fabrication process is simple and carried out at low temperature, which is cost effective, and can potentially be ported to large-area roll-to-roll manufacturing. An encapsulation method to prevent MIM junctions’ degradation has also been developed. Following the successful production of these MIM devices on a rigid substrate, with the fabrication only requiring low-temperature processing, the diodes were successfully fabricated on a flexible substrate with results similar to those fabricated on a...

A simple and elegant method impedance of a typical THz self-complementar to the high-impedance of... more A simple and elegant method impedance of a typical THz self-complementar to the high-impedance of a nanodiode is propos balanced lines emerging from the antenna feed connect the diode, correct for the reactive c antenna impedance and compensate the parasi the diode. Numerical simulations considering with a metal-insulator-metal diode showed that several kΩ can be effectively matched.

Applied Physics Letters, 2016

We report on the fabrication and testing of metal-insulator-metal (MIM) diodes on a flexible subs... more We report on the fabrication and testing of metal-insulator-metal (MIM) diodes on a flexible substrate where the thin insulating layer self-assembles as a monolayer sandwiched between the two metal electrodes. The current-voltage characteristic has a strong asymmetry and non-linearity at zero-bias.

AIP Advances, 2019

This paper reports on the experimental investigation of metal-insulator-metal (MIM) diodes based... more This paper reports on the experimental investigation of metal-insulator-metal (MIM) diodes based on alkyltrichlorosilane self-assembled monolayers (SAMs) with different alkyl chain lengths. The insulating SAM is sandwiched between two metal contacts, Pt and Ti, with different work functions. The electronic properties of the MIM diodes can be tuned by controlling the alkyl chain length of the SAMs to address different constraints in high speed electronics applications. Data fitting of the tunneling current through the MIM junctions using the Fowler-Nordheim model suggests that the device operation is influenced by the barrier heights of the diodes and thicknesses of the SAMs. The current-voltage characteristics achieved in MIM diodes based on alkyltrichlorosilane SAMs make them promising candidates for high speed electronics applications.

The model of a hybrid dc-dc boost converter, which consists of the conventional and a 2-phase int... more The model of a hybrid dc-dc boost converter, which consists of the conventional and a 2-phase interleaved dcdc boost converters, is reported. The efficiency of the hybrid converter is well above 90% and remains so throughout the operating period of the system. The model is simple and compact, and will be very useful in applications where a roundthe-clock high efficiency performance is of paramount importance.

The fabrication of low-cost met (MIM) diodes using a self-assembled mo insulating layer is presen... more The fabrication of low-cost met (MIM) diodes using a self-assembled mo insulating layer is presented. DC and AC analy diodes have excellent non-linear current volta compared to those typically reported, with a ze coefficient ranging from 0.5 V -1 to 5.4 V -1 , volta 1.9 kV/W at a frequency of 1 GHz. The proc fabricating these diodes is simple, cost ef potentially be used in the roll-to-roll manuf diodes. Reliability tests performed on the fabri shows that the OTS layer of the diodes rema high temperature up to approximately 450 °C w in thermal energy harvesting applications, whe be exposed to high temperatures.

An effective impedance matching technique for rectennas (an antenna coupled with rectifier) opera... more An effective impedance matching technique for rectennas (an antenna coupled with rectifier) operating at specific frequencies is presented. The rectifier consists of a MIM junction with a molecular insulator. The method used two coplanar strip lines emerging from the antenna feed-point, to correct for the reactive component of the antenna impedance on one side, and to connect the rectifier and transform its impedance on the other side. Microwave and mm-wave characterization of the devices showed that the output voltage of the impedance matched rectenna is almost an order of magnitude higher than that of a control device without matching network at 20 GHz.

A simple and elegant method impedance of a typical THz self-complementar to the high-impedance of... more A simple and elegant method impedance of a typical THz self-complementar to the high-impedance of a nanodiode is propos balanced lines emerging from the antenna feed connect the diode, correct for the reactive c antenna impedance and compensate the parasi the diode. Numerical simulations considering with a metal-insulator-metal diode showed that several k can be effectively matched.

The fabrication and testing of metal-insulatormetal (MIM) diodes on a flexible substrate for micr... more The fabrication and testing of metal-insulatormetal (MIM) diodes on a flexible substrate for microwave and mm-wave applications are presented. The diodes utilized octadecyltrichlorosilane (OTS), which self assembles to form a thin, pin holes free insulator. Preliminary electrical analysis shows that the diodes have a typical zero bias resistance of approximately 80 k , zero-bias curvature coefficient ( _ZB) of approximately 5.5 V -1 , and voltage responsivity of 3.1 kV/W at a frequency of 1 GHz, and are produced with over 90% device yield. The fabrication process is simple and cost effective, environmentally friendly, and demonstrates the possibility of roll-to-roll volume manufacturing of MIM diodes.

This work presents the fabrication of novel high-frequency low-cost metal-insulator-metal (MIM) d... more This work presents the fabrication of novel high-frequency low-cost metal-insulator-metal (MIM) diodes with the dielectric (insulating) layer formed using a chemical approach at low temperature, rather than using the more aggressive techniques typical of the semiconductor industry. This device is a useful component in a wide range of applications, including radio frequency identification (RFID), high frequency detectors and mixers, and electromagnetic energy harvesting as in (Y. Pan, C. V. Powell, A. M. Song, and C. Balocco, "Micro Rectennas: Brownian Ratchets for Thermal-Energy Harvesting", Appl. Phys. Lett. 105, 253901, 2014).