M. Ahmetoglu - Academia.edu (original) (raw)

Papers by M. Ahmetoglu

Research paper thumbnail of A novel self-powered filterless narrow-band near-infrared photodiode of Cu2S/Si p+-p isotype heterojunction device with very low visible light noise

Research paper thumbnail of Growth and characterization of GaInAsSb solid solutions with composition near the miscibility gap boundary

Fizika (Baku), Sep 1, 2010

Research paper thumbnail of Dark currents in GaSb/GaInAsSb heterojunction photodiodes at high temperatures

Journal of Optoelectronics and Advanced Materials, 2008

Current flow mechanisms have been studied for Liquid Phase Epitaxy (LPE) grown GaSb/GaInAsSb/GaAl... more Current flow mechanisms have been studied for Liquid Phase Epitaxy (LPE) grown GaSb/GaInAsSb/GaAlAsSb heterostructures lattice-matched to GaSb substrates. The epitaxial layers have shown a good surface morphology and straight interface lines. The dark current mechanisms were investigated at several temperatures. The qualitative comparison of experimental results with theory shows that, the high temperature region the diffusion mechanism of the current flow dominates in both, forward and reverse biases. The tunneling current becomes substantial at peak junction electric fields as low as 10 4 V/cm due to the small direct energy gaps and small effective masses of the structure tested.

Research paper thumbnail of Dark currents in the uncooled inas / InAsAbP photodiodes for the spectral range 1.6 -3.5 μm

Journal of Optoelectronics and Advanced Materials, 2007

The electrical characteristics of photodiode structures on the base of InAS/lnAsSbP heterojunctio... more The electrical characteristics of photodiode structures on the base of InAS/lnAsSbP heterojunctions, that have a high room-temperature differential resistance and operate in the mid-infrared region over the wavelength range 1.6-3.5 μm are reported. As a result of C-Vmeasurements, the obtained p-n heterojunctions were abrupt, with 1/C 2 ∼V, and the impurity concentration in the weakly doped region was (5-7)x10 15 cm -3 at room temperature. An experimental investigation of current-voltage characteristics has been done in the temperature range 77-340 K, and have been determined the mechanism of the flow of dark currents in InAS/lnAsSbP heterojunction photodiodes.

Research paper thumbnail of Photodiodes for Detecting the Emission of Quantum-Sized Disc Lasers Operating in the Whispering Gallery Modes (2.2–2.3 μm)

Semiconductors, 2020

Photodiodes based on solid solutions in the GaSb-InAs system are for the first time applied to st... more Photodiodes based on solid solutions in the GaSb-InAs system are for the first time applied to study the spectral characteristics of single and coupled whispering-gallery-mode (WGM) lasers emitting in a range of 2.2-2.3 μm. The capacity of photodiodes with a photosensitive area 2.0 mm in diameter is C = 520 pF at U =-2 V, which corresponds to a time constant of τ = 53 ns. It is shown that the parameters of the fabricated photodiodes make it possible to detect the emission of quantum-sized disc lasers at room temperature not using cryogenic cooling.

Research paper thumbnail of Photoelectrical properties of fabricated ZnS/Si heterojunction device using thermionic vacuum arc method

Superlattices and Microstructures, 2018

properties of fabricated ZnS/Si heterojunction device using thermionic vacuum arc method, Superla... more properties of fabricated ZnS/Si heterojunction device using thermionic vacuum arc method, Superlattices and Microstructures (2018),

Research paper thumbnail of The characteristics of ZnS/Si heterojunction diode fabricated by thermionic vacuum arc

Journal of Alloys and Compounds, 2017

Abstract ZnS/p-Si heterojunction diode has been successfully fabricated by depositing the ZnS thi... more Abstract ZnS/p-Si heterojunction diode has been successfully fabricated by depositing the ZnS thin films on p-type Si substrates using thermionic vacuum arc technique (TVA). The structural analysis was performed with X-ray diffraction (XRD) and Atomic force microscopy (AFM). The results revealed that ZnS thin film demonstrates nano-crystalline behavior with very smooth and homogeneous surface properties. The type was determined as n-type and the carrier concentration was found approximately 3.1 × 1017 cm−3 of the ZnS thin film by means of Hall Effect measurement. The dark current-voltage (I-V) and the capacitance-voltage (C-V) measurements with different frequencies were performed to determine the characteristics of the ZnS/p-Si heterojunction diode at room temperature. I-V results show that the diode has a good rectifying characteristic with excellent rectification ratio. The electrical parameters of the diode have been obtained by using current transport mechanism. It was found that the barrier height calculated from dark I-V measurements is in good agreement with the value obtained from C-V measurements at a frequency of 1.5 MHz. The series resistance and the built in potential of the fabricated diode were calculated as 3.6 kΩ and 0.7 V using Cheung and Cheung's equation and C-V measurement, respectively. The low cost and effective film production method were utilized to fabrication of heterojunction diode and to investigate characteristics.

Research paper thumbnail of Electrical Properties Inorganic-on-Organic Hybrid GaAs/Graphene Oxide Schottky Barrier Diode

Journal of Nanoelectronics and Optoelectronics, 2016

Research paper thumbnail of Poly(ethylene glycol dimethacrylate-co-1-vinyl-1,2,4-triazole/ carbon nanotube, single-walled)/n-GaAs Diode Formed by Surface Polymerization

Acta Physica Polonica A, 2016

Poly(ethylene glycol dimethacrylate-co-1-vinyl-1,2,4-triazole/carbon nanotube, single-walled)/n-G... more Poly(ethylene glycol dimethacrylate-co-1-vinyl-1,2,4-triazole/carbon nanotube, single-walled)/n-GaAs ([P(EGDMA-VTAZ)-CNSW]/n-GaAs) diode was fabricated by using surface polymerization method. Electrical properties were carried out at several temperatures. Dark current mechanisms were investigated by using current-voltage (I-V) measurements. It was shown that the fabricated structure exhibited rectification behaviour that makes it a good candidate for electronic device applications.

Research paper thumbnail of The Electrical Properties of Au/P3HT/<I><SUP>n</SUP></I>-Type Si Schottky Barrier Diode

Journal of Nanoelectronics and Optoelectronics, 2016

Research paper thumbnail of Electrical Characteristics and Temperature Dependence of Photovoltaic Parameters of GaInAsSb Based TPV Diode

Acta Physica Polonica A, 2016

In this paper, electrical characterization of low bandgap GaInAsSb based thermophotovoltaic (TPV)... more In this paper, electrical characterization of low bandgap GaInAsSb based thermophotovoltaic (TPV) diodes were investigated, as well as the temperature dependence of photovoltaic parameters such as short circuit current (Isc) and open circuit voltage (Voc). Investigation of the dark current mechanisms of the structure was carried out at several temperatures. The effect of light intensity on current-voltage characteristics was also investigated.

Research paper thumbnail of Gallium Antimonide-Based Photodiodes and Thermophotovoltaic Devices

AIP Conference Proceedings, 2007

Gallium Antimonide‐Based Photodiodes and Thermophotovoltaic Devices. [AIP Conference Proceedings ... more Gallium Antimonide‐Based Photodiodes and Thermophotovoltaic Devices. [AIP Conference Proceedings 899, 447 (2007)]. Muhitdin Ahmetoglu (Afrailov), Igor A. Andreev, Ekaterina V. Kunitsyna, Maya P. Mikhailova, Yury P. Yakovlev, Kadir Erturk. Abstract. ...

Research paper thumbnail of The Electrical Properties of Au/P3HT/n-GaAs Schottky Barrier Diode

Acta Physica Polonica A, 2015

In this study, we investigated the electrical properties of the Au/P3HT/n-GaAs Schottky diode at ... more In this study, we investigated the electrical properties of the Au/P3HT/n-GaAs Schottky diode at room temperature by using current-voltage method. The values of ideality factor and barrier height of the diode were found to be 2.45 and 0.85 eV, respectively. n ideality factor greater than unity indicates that the diode exhibits non-ideal current-voltage behavior. This behavior results from the effect of series resistance and the presence of an interfacial layer. These values were also determined from the Cheung functions and the Norde method due to the non-ideal behavior of the diode and it was seen that there was an agreement with series resistance. Also the interface states energy distribution of the diode was determined from the forward bias I-V measurements by taking into account the bias dependence of the effective barrier height. The obtained electrical parameters of the Au/P3HT/n-GaAs Schottky diode are higher than that of the conventional Au/n-GaAs Schottky diodes.

Research paper thumbnail of Electrical and Optical Characteristics of n-GaSb/n-GaIn 0.24 AsSb/p-GaAl 0.34 AsSb Heterostructure Photodiode

Acta Physica Polonica A, 2015

In the present paper, electrical and optical properties of n-GaSb/n-GaIn0.24AsSb/p-GaAl0.34AsSb d... more In the present paper, electrical and optical properties of n-GaSb/n-GaIn0.24AsSb/p-GaAl0.34AsSb double heterostructure (DH) with a diameter of 0.3 mm are reported. The current-voltage (I-V) characteristics of the structure were investigated at several temperatures in both, dark and under the illumination conditions. The eect of illumination was studied at dierent intensity values. Short circuit current and open circuit voltage as a function of intensity of incident light in photovoltaic mode are investigated.

Research paper thumbnail of DARK CURRENTS AND IMPACT IONIZATION COEFFICIENTS IN THE InP-InGaAsP DOUBLE HETEROSTRUCTURES

International Journal of Modern Physics B, 2006

The dependence of reverse-biased leakage current on both voltage and temperature for InP - In x G... more The dependence of reverse-biased leakage current on both voltage and temperature for InP - In x Ga 1-x As y P 1-y DH (double heterostructures) has been analyzed. We find that at the whole of the temperature range and at a wide range of reverse bias voltages, the reverse current varies exponentially with applied voltage, indicating that the band-to-band tunneling current mechanism prevails. An agreement is obtained between theory and experimental results. The tunneling current becomes substantial at peak junction electric fields as low as 105 V/m due to the small direct energy gaps and small effective masses of the structures tested. The process of breakdown in the investigated structures was of the avalanche type. The impact ionization coefficients in In x Ga 1-x As y P 1-y have been experimentally determined for composition x=0.68.

Research paper thumbnail of Avalanche photodiodes for electromagnetic calorimeters

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2007

Hamamatsu S8148 silicon avalanche photodiode (APD) working in proportional mode has been chosen a... more Hamamatsu S8148 silicon avalanche photodiode (APD) working in proportional mode has been chosen as readout device for the PbWO4 crystals in the barrel of the CMS electromagnetic calorimeter (ECAL). High hadron fluences strongly affect the main parameters of both the scintillation crystals and the silicon detectors. In this work, we offer a new zinc sulfide–silicon (ZnS–Si) isotype heterojunction APD structure

Research paper thumbnail of The electrical characterization of electrodeposited Ni thin film on silicon: Schottky Barrier diodes

ABSTRACT A Ni/n-Si Schottky barrier diode was produced by electrodeposition technique from the el... more ABSTRACT A Ni/n-Si Schottky barrier diode was produced by electrodeposition technique from the electrolyte containing nickel ions under galvanostatic control. The deposition was carried out in a three-electrode cell at room temperature. The electrical characteristics of the Schottky diodes have been investigated using current-voltage (l-V) and capacitance-voltage (C-V) measurements. Ni/n-Si/AuSb diode current-voltage characteristics display low reverse bias leakage currents. The barrier height and ideality factor (n) were obtained 0.60 eV and 3.28 respectively. The high ideality factor value was attributed to oxide layer at the metal semiconductor interface.

Research paper thumbnail of Narrow gap III–V materials for infrared photodiodes and thermophotovoltaic cells

Optical Materials, 2010

The paper describes liquid phase epitaxial growth and characterization of the GaSb-and InAs-relat... more The paper describes liquid phase epitaxial growth and characterization of the GaSb-and InAs-related materials for the photodiodes and thermophotovoltaic applications. It was shown that doping of the melt with holmium results in obtaining the high purity GaInAsSb and InAs layers. The passivation with the 1 M Na 2 S aqueous solution makes it possible to prepare flat growth surfaces of GaSb(1 0 0) and InAs(1 0 0) substrates after annealing. A reproducible technique has been developed for fabrication of the high-efficiency GaInAsSb/GaAlAsSb and InAs/InAsSbP photodiodes with the long-wavelength photosensitivity edge of 2.4 and 3.8 lm, respectively. Room temperature detectivity in the spectral peak reaches D* = (0.8-1.0) Â 10 11 W À1 cm Hz 1/2 for the GaInAsSb/GaAlAsSb photodiodes and D* = (3.0-5.0) Â 10 9 W À1 cm Hz 1/2 for the InAs/InAsSbP devices. We have adapted the technology for thermophotovoltaic cells operating at an emitter temperature of 1000-1700°C.

Research paper thumbnail of Electrical and optical characteristics of the InAs/InAs0.7Sb0.1P0.2 single heterojunction photodiodes for the spectral range 1.6–3.5μm

Infrared Physics & Technology, 2012

The electrical end optical characteristics of InAs/InAs 0.7 Sb 0.1 P 0.2 heterojunctions were stu... more The electrical end optical characteristics of InAs/InAs 0.7 Sb 0.1 P 0.2 heterojunctions were studied. The dark current mechanisms in the heterostructures were investigated at several temperatures. The experimental results shows that, the low temperature region the tunneling mechanism of the current flow dominates in both, forward and reverse biases. At high temperatures region and in the range of voltage from 0.1 V to 1 V, the reverse current was defined by diffusion mechanism.

Research paper thumbnail of Electrical and optical properties of the GaInAsSb-based heterojunctions for infrared photodiode and thermophotovoltaic cell application

Infrared Physics & Technology, 2010

ABSTRACT The electrical end optical characteristics of a type II double heterojunction (DH) in th... more ABSTRACT The electrical end optical characteristics of a type II double heterojunction (DH) in the GaSb/GaInAsSb/GaAlAsSb system with staggered band alignment were studied. An analysis of the photodiodes performance through the investigation into electrical and optical characteristics was carried out. The dark current mechanisms in the heterostructures were investigated at several temperatures. The experimental results show that at the low temperature region, the tunneling mechanism of the current flow dominates in both forward and reverse biases. At high temperatures region and in the range of voltage from 0.1 V to 1 V, the reverse current was defined by generation of carriers in the depletion region. Have been estimated the temperature coefficient of the shift of the long-wavelength edge of the spectral sensitivity at half-maximum as Δλ/ΔT = 1.6 nm/K. Quantum efficiency of 0.6–0.7 for the investigated photodiodes was reached without any antireflection coating. For GaSb/GaInAsSb/GaAlAsSb TPV cells, the internal quantum efficiency of 90% was achieved at wavelengths between 1.2 and 1.6 μm.

Research paper thumbnail of A novel self-powered filterless narrow-band near-infrared photodiode of Cu2S/Si p+-p isotype heterojunction device with very low visible light noise

Research paper thumbnail of Growth and characterization of GaInAsSb solid solutions with composition near the miscibility gap boundary

Fizika (Baku), Sep 1, 2010

Research paper thumbnail of Dark currents in GaSb/GaInAsSb heterojunction photodiodes at high temperatures

Journal of Optoelectronics and Advanced Materials, 2008

Current flow mechanisms have been studied for Liquid Phase Epitaxy (LPE) grown GaSb/GaInAsSb/GaAl... more Current flow mechanisms have been studied for Liquid Phase Epitaxy (LPE) grown GaSb/GaInAsSb/GaAlAsSb heterostructures lattice-matched to GaSb substrates. The epitaxial layers have shown a good surface morphology and straight interface lines. The dark current mechanisms were investigated at several temperatures. The qualitative comparison of experimental results with theory shows that, the high temperature region the diffusion mechanism of the current flow dominates in both, forward and reverse biases. The tunneling current becomes substantial at peak junction electric fields as low as 10 4 V/cm due to the small direct energy gaps and small effective masses of the structure tested.

Research paper thumbnail of Dark currents in the uncooled inas / InAsAbP photodiodes for the spectral range 1.6 -3.5 μm

Journal of Optoelectronics and Advanced Materials, 2007

The electrical characteristics of photodiode structures on the base of InAS/lnAsSbP heterojunctio... more The electrical characteristics of photodiode structures on the base of InAS/lnAsSbP heterojunctions, that have a high room-temperature differential resistance and operate in the mid-infrared region over the wavelength range 1.6-3.5 μm are reported. As a result of C-Vmeasurements, the obtained p-n heterojunctions were abrupt, with 1/C 2 ∼V, and the impurity concentration in the weakly doped region was (5-7)x10 15 cm -3 at room temperature. An experimental investigation of current-voltage characteristics has been done in the temperature range 77-340 K, and have been determined the mechanism of the flow of dark currents in InAS/lnAsSbP heterojunction photodiodes.

Research paper thumbnail of Photodiodes for Detecting the Emission of Quantum-Sized Disc Lasers Operating in the Whispering Gallery Modes (2.2–2.3 μm)

Semiconductors, 2020

Photodiodes based on solid solutions in the GaSb-InAs system are for the first time applied to st... more Photodiodes based on solid solutions in the GaSb-InAs system are for the first time applied to study the spectral characteristics of single and coupled whispering-gallery-mode (WGM) lasers emitting in a range of 2.2-2.3 μm. The capacity of photodiodes with a photosensitive area 2.0 mm in diameter is C = 520 pF at U =-2 V, which corresponds to a time constant of τ = 53 ns. It is shown that the parameters of the fabricated photodiodes make it possible to detect the emission of quantum-sized disc lasers at room temperature not using cryogenic cooling.

Research paper thumbnail of Photoelectrical properties of fabricated ZnS/Si heterojunction device using thermionic vacuum arc method

Superlattices and Microstructures, 2018

properties of fabricated ZnS/Si heterojunction device using thermionic vacuum arc method, Superla... more properties of fabricated ZnS/Si heterojunction device using thermionic vacuum arc method, Superlattices and Microstructures (2018),

Research paper thumbnail of The characteristics of ZnS/Si heterojunction diode fabricated by thermionic vacuum arc

Journal of Alloys and Compounds, 2017

Abstract ZnS/p-Si heterojunction diode has been successfully fabricated by depositing the ZnS thi... more Abstract ZnS/p-Si heterojunction diode has been successfully fabricated by depositing the ZnS thin films on p-type Si substrates using thermionic vacuum arc technique (TVA). The structural analysis was performed with X-ray diffraction (XRD) and Atomic force microscopy (AFM). The results revealed that ZnS thin film demonstrates nano-crystalline behavior with very smooth and homogeneous surface properties. The type was determined as n-type and the carrier concentration was found approximately 3.1 × 1017 cm−3 of the ZnS thin film by means of Hall Effect measurement. The dark current-voltage (I-V) and the capacitance-voltage (C-V) measurements with different frequencies were performed to determine the characteristics of the ZnS/p-Si heterojunction diode at room temperature. I-V results show that the diode has a good rectifying characteristic with excellent rectification ratio. The electrical parameters of the diode have been obtained by using current transport mechanism. It was found that the barrier height calculated from dark I-V measurements is in good agreement with the value obtained from C-V measurements at a frequency of 1.5 MHz. The series resistance and the built in potential of the fabricated diode were calculated as 3.6 kΩ and 0.7 V using Cheung and Cheung's equation and C-V measurement, respectively. The low cost and effective film production method were utilized to fabrication of heterojunction diode and to investigate characteristics.

Research paper thumbnail of Electrical Properties Inorganic-on-Organic Hybrid GaAs/Graphene Oxide Schottky Barrier Diode

Journal of Nanoelectronics and Optoelectronics, 2016

Research paper thumbnail of Poly(ethylene glycol dimethacrylate-co-1-vinyl-1,2,4-triazole/ carbon nanotube, single-walled)/n-GaAs Diode Formed by Surface Polymerization

Acta Physica Polonica A, 2016

Poly(ethylene glycol dimethacrylate-co-1-vinyl-1,2,4-triazole/carbon nanotube, single-walled)/n-G... more Poly(ethylene glycol dimethacrylate-co-1-vinyl-1,2,4-triazole/carbon nanotube, single-walled)/n-GaAs ([P(EGDMA-VTAZ)-CNSW]/n-GaAs) diode was fabricated by using surface polymerization method. Electrical properties were carried out at several temperatures. Dark current mechanisms were investigated by using current-voltage (I-V) measurements. It was shown that the fabricated structure exhibited rectification behaviour that makes it a good candidate for electronic device applications.

Research paper thumbnail of The Electrical Properties of Au/P3HT/<I><SUP>n</SUP></I>-Type Si Schottky Barrier Diode

Journal of Nanoelectronics and Optoelectronics, 2016

Research paper thumbnail of Electrical Characteristics and Temperature Dependence of Photovoltaic Parameters of GaInAsSb Based TPV Diode

Acta Physica Polonica A, 2016

In this paper, electrical characterization of low bandgap GaInAsSb based thermophotovoltaic (TPV)... more In this paper, electrical characterization of low bandgap GaInAsSb based thermophotovoltaic (TPV) diodes were investigated, as well as the temperature dependence of photovoltaic parameters such as short circuit current (Isc) and open circuit voltage (Voc). Investigation of the dark current mechanisms of the structure was carried out at several temperatures. The effect of light intensity on current-voltage characteristics was also investigated.

Research paper thumbnail of Gallium Antimonide-Based Photodiodes and Thermophotovoltaic Devices

AIP Conference Proceedings, 2007

Gallium Antimonide‐Based Photodiodes and Thermophotovoltaic Devices. [AIP Conference Proceedings ... more Gallium Antimonide‐Based Photodiodes and Thermophotovoltaic Devices. [AIP Conference Proceedings 899, 447 (2007)]. Muhitdin Ahmetoglu (Afrailov), Igor A. Andreev, Ekaterina V. Kunitsyna, Maya P. Mikhailova, Yury P. Yakovlev, Kadir Erturk. Abstract. ...

Research paper thumbnail of The Electrical Properties of Au/P3HT/n-GaAs Schottky Barrier Diode

Acta Physica Polonica A, 2015

In this study, we investigated the electrical properties of the Au/P3HT/n-GaAs Schottky diode at ... more In this study, we investigated the electrical properties of the Au/P3HT/n-GaAs Schottky diode at room temperature by using current-voltage method. The values of ideality factor and barrier height of the diode were found to be 2.45 and 0.85 eV, respectively. n ideality factor greater than unity indicates that the diode exhibits non-ideal current-voltage behavior. This behavior results from the effect of series resistance and the presence of an interfacial layer. These values were also determined from the Cheung functions and the Norde method due to the non-ideal behavior of the diode and it was seen that there was an agreement with series resistance. Also the interface states energy distribution of the diode was determined from the forward bias I-V measurements by taking into account the bias dependence of the effective barrier height. The obtained electrical parameters of the Au/P3HT/n-GaAs Schottky diode are higher than that of the conventional Au/n-GaAs Schottky diodes.

Research paper thumbnail of Electrical and Optical Characteristics of n-GaSb/n-GaIn 0.24 AsSb/p-GaAl 0.34 AsSb Heterostructure Photodiode

Acta Physica Polonica A, 2015

In the present paper, electrical and optical properties of n-GaSb/n-GaIn0.24AsSb/p-GaAl0.34AsSb d... more In the present paper, electrical and optical properties of n-GaSb/n-GaIn0.24AsSb/p-GaAl0.34AsSb double heterostructure (DH) with a diameter of 0.3 mm are reported. The current-voltage (I-V) characteristics of the structure were investigated at several temperatures in both, dark and under the illumination conditions. The eect of illumination was studied at dierent intensity values. Short circuit current and open circuit voltage as a function of intensity of incident light in photovoltaic mode are investigated.

Research paper thumbnail of DARK CURRENTS AND IMPACT IONIZATION COEFFICIENTS IN THE InP-InGaAsP DOUBLE HETEROSTRUCTURES

International Journal of Modern Physics B, 2006

The dependence of reverse-biased leakage current on both voltage and temperature for InP - In x G... more The dependence of reverse-biased leakage current on both voltage and temperature for InP - In x Ga 1-x As y P 1-y DH (double heterostructures) has been analyzed. We find that at the whole of the temperature range and at a wide range of reverse bias voltages, the reverse current varies exponentially with applied voltage, indicating that the band-to-band tunneling current mechanism prevails. An agreement is obtained between theory and experimental results. The tunneling current becomes substantial at peak junction electric fields as low as 105 V/m due to the small direct energy gaps and small effective masses of the structures tested. The process of breakdown in the investigated structures was of the avalanche type. The impact ionization coefficients in In x Ga 1-x As y P 1-y have been experimentally determined for composition x=0.68.

Research paper thumbnail of Avalanche photodiodes for electromagnetic calorimeters

Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2007

Hamamatsu S8148 silicon avalanche photodiode (APD) working in proportional mode has been chosen a... more Hamamatsu S8148 silicon avalanche photodiode (APD) working in proportional mode has been chosen as readout device for the PbWO4 crystals in the barrel of the CMS electromagnetic calorimeter (ECAL). High hadron fluences strongly affect the main parameters of both the scintillation crystals and the silicon detectors. In this work, we offer a new zinc sulfide–silicon (ZnS–Si) isotype heterojunction APD structure

Research paper thumbnail of The electrical characterization of electrodeposited Ni thin film on silicon: Schottky Barrier diodes

ABSTRACT A Ni/n-Si Schottky barrier diode was produced by electrodeposition technique from the el... more ABSTRACT A Ni/n-Si Schottky barrier diode was produced by electrodeposition technique from the electrolyte containing nickel ions under galvanostatic control. The deposition was carried out in a three-electrode cell at room temperature. The electrical characteristics of the Schottky diodes have been investigated using current-voltage (l-V) and capacitance-voltage (C-V) measurements. Ni/n-Si/AuSb diode current-voltage characteristics display low reverse bias leakage currents. The barrier height and ideality factor (n) were obtained 0.60 eV and 3.28 respectively. The high ideality factor value was attributed to oxide layer at the metal semiconductor interface.

Research paper thumbnail of Narrow gap III–V materials for infrared photodiodes and thermophotovoltaic cells

Optical Materials, 2010

The paper describes liquid phase epitaxial growth and characterization of the GaSb-and InAs-relat... more The paper describes liquid phase epitaxial growth and characterization of the GaSb-and InAs-related materials for the photodiodes and thermophotovoltaic applications. It was shown that doping of the melt with holmium results in obtaining the high purity GaInAsSb and InAs layers. The passivation with the 1 M Na 2 S aqueous solution makes it possible to prepare flat growth surfaces of GaSb(1 0 0) and InAs(1 0 0) substrates after annealing. A reproducible technique has been developed for fabrication of the high-efficiency GaInAsSb/GaAlAsSb and InAs/InAsSbP photodiodes with the long-wavelength photosensitivity edge of 2.4 and 3.8 lm, respectively. Room temperature detectivity in the spectral peak reaches D* = (0.8-1.0) Â 10 11 W À1 cm Hz 1/2 for the GaInAsSb/GaAlAsSb photodiodes and D* = (3.0-5.0) Â 10 9 W À1 cm Hz 1/2 for the InAs/InAsSbP devices. We have adapted the technology for thermophotovoltaic cells operating at an emitter temperature of 1000-1700°C.

Research paper thumbnail of Electrical and optical characteristics of the InAs/InAs0.7Sb0.1P0.2 single heterojunction photodiodes for the spectral range 1.6–3.5μm

Infrared Physics & Technology, 2012

The electrical end optical characteristics of InAs/InAs 0.7 Sb 0.1 P 0.2 heterojunctions were stu... more The electrical end optical characteristics of InAs/InAs 0.7 Sb 0.1 P 0.2 heterojunctions were studied. The dark current mechanisms in the heterostructures were investigated at several temperatures. The experimental results shows that, the low temperature region the tunneling mechanism of the current flow dominates in both, forward and reverse biases. At high temperatures region and in the range of voltage from 0.1 V to 1 V, the reverse current was defined by diffusion mechanism.

Research paper thumbnail of Electrical and optical properties of the GaInAsSb-based heterojunctions for infrared photodiode and thermophotovoltaic cell application

Infrared Physics & Technology, 2010

ABSTRACT The electrical end optical characteristics of a type II double heterojunction (DH) in th... more ABSTRACT The electrical end optical characteristics of a type II double heterojunction (DH) in the GaSb/GaInAsSb/GaAlAsSb system with staggered band alignment were studied. An analysis of the photodiodes performance through the investigation into electrical and optical characteristics was carried out. The dark current mechanisms in the heterostructures were investigated at several temperatures. The experimental results show that at the low temperature region, the tunneling mechanism of the current flow dominates in both forward and reverse biases. At high temperatures region and in the range of voltage from 0.1 V to 1 V, the reverse current was defined by generation of carriers in the depletion region. Have been estimated the temperature coefficient of the shift of the long-wavelength edge of the spectral sensitivity at half-maximum as Δλ/ΔT = 1.6 nm/K. Quantum efficiency of 0.6–0.7 for the investigated photodiodes was reached without any antireflection coating. For GaSb/GaInAsSb/GaAlAsSb TPV cells, the internal quantum efficiency of 90% was achieved at wavelengths between 1.2 and 1.6 μm.