J. Serafińczuk | Wrocław University of Technology (original) (raw)
Papers by J. Serafińczuk
Acta Physica Polonica A, 2022
Growth characteristics of AlGaN layers in different conditions: pressure and ammonia flow were pr... more Growth characteristics of AlGaN layers in different conditions: pressure and ammonia flow were presented. The structures containing the AlN buffer and the AlGaN layer were grown by metalorganic vapor phase epitaxy. The goal was to find the growth conditions for AlGaN with stable 60% of aluminium and determine the aluminium concentration deviation while changing two parameters. Pressure showed bigger influence on aluminium incorporation, layer quality and surface roughness than ammonia.
Anisotropic strain relaxation and surface morphology
Optica Applicata, 2020
The presented paper deals with the measurement methodologies of the structural properties of poro... more The presented paper deals with the measurement methodologies of the structural properties of porous anodic alumina (PAA) films filled with YAlO3:Tb3+ composite using X-ray diffraction, atomic force microscopy and scanning electron microscopy. It shows that the deposited material does not uniformly fill the porous volume of the anodic alumina film and the part of it forms a thick layer on the PAA surface. The aim of this work is to show the differences in the XRD response obtained at different angles of incidence of the excitation beam for the PAA/YAlO3:Tb3+ system. Furthermore, this simple approach enables separation of the signal from both regions on the surface and inside the PAA pores, providing more accurate data interpretation. It reveals that the crystallization of the material on the PAA surface and within the pores is different.
Journal of Electrical Engineering, 2014
GaInNAs alloys are mostly used as an active part of light sources for long wavelength telecom app... more GaInNAs alloys are mostly used as an active part of light sources for long wavelength telecom applications. Beside this, these materials are used as thin quantum wells (QWs), and a need is to grow thick layers of such semiconductor alloys for photodetectors and photovoltaic cells applications. However, structural characterization of the GaInNAs layers is hindered by non-homogeneity of the In and N distributions along the layer. In this work the challenges of the structural characterization of doped thick GaInNAs layers grown by atmospheric pressure metalorganic vapour phase epitaxy (APMOVPE) will be presented
Opto-Electronics Review, 2008
The nitrogen-containing conventional AIIIBV semiconductor alloys, so-called diluted nitrides (AII... more The nitrogen-containing conventional AIIIBV semiconductor alloys, so-called diluted nitrides (AIIIBV-N), have been extensively studied recently. Unusual properties of these materials make them very promising for applications in lasers and very efficient multijunction solar cells. This work presents the technology and properties of undoped GaAs1-xNx/GaAs heterostructures used as active regions in the construction of metal-semiconductor-metal (MSM) photodetectors. The atmospheric pressure metal organic vapour phase epitaxy (APMOVPE) was applied for growing MSM test structures. Their structural and optical properties were examined using high resolution X-ray diffraction (HRXRD), photoluminescence (PL), and photoreflectance spectroscopy (PR). Chemical wet etching was applied for forming an active region and a multifinger Schottky metallization was used as MSM contacts. Dark and illuminated current-voltage characteristics were measured. Based on the obtained results, the main detector pa...
![Research paper thumbnail of Influence of Annealing on Excitation of Terbium Luminescence in YAlO[sub 3] Films Deposited onto Porous Anodic Alumina](https://attachments.academia-assets.com/105358583/thumbnails/1.jpg)
](Journal of The Electrochemical Society, 2010
Terbium-doped yttrium-aluminum oxide films were synthesized by spin-on deposition on porous anodi... more Terbium-doped yttrium-aluminum oxide films were synthesized by spin-on deposition on porous anodic alumina grown on a silicon wafer and annealed from 400 to 1100°C. An influence of the annealing temperature on the terbium photoluminescence ͑PL͒ was studied using two-dimensional PL excitation and time-resolved spectroscopy. Further, a comparison of thermal quenching data for the most intensive 5 D 4 → 7 F 5 luminescence band of Tb 3+ ions was performed for 10-300 K. From the resultant data, the mechanisms of Tb excitation and its dependence on the annealing conditions are proposed and discussed.
Materials Science in Semiconductor Processing
Acta Physica Polonica A
The structural properties of AlGaN layers deposited on high-and low-temperature grown AlN buffer ... more The structural properties of AlGaN layers deposited on high-and low-temperature grown AlN buffer were analysed. Modulated ammonia flow method of preparing AlN buffer was compared with a constant ammonia flow process using metalorganic vapour phase epitaxy. Low-temperature growth of the AlN buffer led to an increase of surface roughness, nevertheless crystal quality was comparable to the AlN buffer grown in high-temperature. Low-temperature nucleation AlN on sapphire substrates was required due to differences in thermal expansion and possible reduction of the number of dislocation. Modulated ammonia flow method provides an alternative approach for the AlN buffer growth at reduced reactor temperature.
Journal of Applied Physics
Selection of a suitable chemical etching method for threading dislocations density estimation is ... more Selection of a suitable chemical etching method for threading dislocations density estimation is crucial for the structural characterization of epilayers grown by MOVPE and thus further for device fabrication. In this work, threading dislocations density in single layer and Al x Ga 1Àx N/GaN periodical heterostructures has been investigated by means of chemical etching and XRD analysis. For chemical etching, two types of agents have been used: phosphoric acid (220 C=7:5 min) and a molten mixture of KOH-NaOH (440 C=2:5 min). Estimation of dislocation density has been carried out on the basis of SEM images. It was shown that defect-selective etching in molten alkaline solution is more effective than etching in phosphoric acid and provides more accurate data that are in agreement with data obtained from XRD characterization.
Advances in Electrical and Electronic Engineering
In this work, the thermal synthesis and characterization of gallium oxide and indium oxide nanowi... more In this work, the thermal synthesis and characterization of gallium oxide and indium oxide nanowires using vapour-liquid-solid mechanism at atmospheric pressure were described. Au nanoislands formed by the solid-state dewetting process of various thickness metal layer were applied as growth catalyst of nanowires while high-purity metal reactants (In, Ga) were applied as AIII precursors. The catalytic layer thickness influence on the morphology of investigated nanostructures was studied. Material composition and structural properties were used for crystallographic quality of AIII-oxide nanowires examination.
Materials Science-Poland
An attempt has been undertaken to produce gallium oxide nanowires by thermal synthesis from metal... more An attempt has been undertaken to produce gallium oxide nanowires by thermal synthesis from metallic gallium source at atmospheric pressure. Silicon substrates of (1 0 0) and (1 1 1) orientation with and without silicon oxide layers (0.5 μm) were used as support. Evaporated thin gold films were deposited on the top of those silicon carriers as a catalytic agent. After thermal treatment by Rapid Thermal Processing RTP (at various temperatures and times), which was applied to make small Au islands with the diameters of about several tens of nanometers, the substrate surfaces were observed by SEM. The Ga
Applied Physics Letters, 2008
Elektronika Konstrukcje Technologie Zastosowania, 2008
Journal of Crystal Growth, 2015
This paper presents advantages of employing the wavelet method in X-ray high-resolution image ana... more This paper presents advantages of employing the wavelet method in X-ray high-resolution image analysis of nanostructures. It is shown that many more details of the structure examined can be distin- guished in rocking curves (RC) as well as in reciprocal space maps (RSM) after application of the numerical procedure. The method proposed seems to be particularly suitable for imperfect epitaxial layers having significant lattice mismatch with respect to substrate. By means of the wavelet analysis of the X-ray images using de-noising procedure details invisible in raw pictures can be detected such as thickness fringes, gradient of lattice parameters etc., and duration of measurements can be shortened.
X-ray reflectivity (XRR) is one of the primary measurement techniques for thickness calculation o... more X-ray reflectivity (XRR) is one of the primary measurement techniques for thickness calculation of thin films and multilayer period determination. This technique can also be used for the analysis of organic thin film multilayer structures. In this method, the accuracy of thickness calculation depends on precision of the determination of the local maxima of XRR curve. The analysis of the XRR curves is cumbersome because of the noise which is recorded while measurement. It can be improved using computer data analysis algorithms for noise reduction and determination of the local maxima on the XRR curve. One of such algorithms, widely used in the data spectroscopy analysis, is Savitzky–Golay (S–G) algorithm. In this paper, the application of S–G algorithm for thickness determination of self-assembled ion liquid nanolayer of dimethyldiallylammonium chloride (PDDA) is shown.
Properties of dilute nitrides material system like large discontinuity of a conduction band (due ... more Properties of dilute nitrides material system like large discontinuity of a conduction band (due to high electronegativity of nitrogen) [1], large band gap bowing coefficient [2], increased electron effective mass [3], large scattering rate (connected with a small radius of nitrogen atom in comparison with the others V group atoms) [4] provide a way to novel applications: telecommunications lasers [1], heterojunction bipolar transistors [5] and very efficient solar cells [6]. InGaAsN is a very promising, lattice matched to GaAs and In0.5Ga0.5P material with band gap about 1 eV. The control of indium and nitrogen amounts in the InGaAsN quaternary alloy offers the ability to tailor the value of band gap and positions of valence and conduction band edges. Main advantage of dilute nitrides is a large reduction of band gap caused by nitrogen introduction (about ~150 meV/% of N). The technology of GaAs is better developed and still much cheaper than indium phosphide and allow to fabricate...
2007 International Students and Young Scientists Workshop on Photonics and Microsystems, 2007
High temperature gallium nitride (HT-GaN) layers were grown by HVPE (hydride vapor phase epitaxy)... more High temperature gallium nitride (HT-GaN) layers were grown by HVPE (hydride vapor phase epitaxy) method on low temperature GaN (LT-GaN) buffer layers deposited by HVPE or MOVPE method and on double MOVPE LT-GaN/AIN buffers. The (0001) sapphire substrates were applied. The HCl flow rate and deposition time intervals of nucleation layer deposition were varied in the range of 8-10 ml/min
Acta Physica Polonica A, 2022
Growth characteristics of AlGaN layers in different conditions: pressure and ammonia flow were pr... more Growth characteristics of AlGaN layers in different conditions: pressure and ammonia flow were presented. The structures containing the AlN buffer and the AlGaN layer were grown by metalorganic vapor phase epitaxy. The goal was to find the growth conditions for AlGaN with stable 60% of aluminium and determine the aluminium concentration deviation while changing two parameters. Pressure showed bigger influence on aluminium incorporation, layer quality and surface roughness than ammonia.
Anisotropic strain relaxation and surface morphology
Optica Applicata, 2020
The presented paper deals with the measurement methodologies of the structural properties of poro... more The presented paper deals with the measurement methodologies of the structural properties of porous anodic alumina (PAA) films filled with YAlO3:Tb3+ composite using X-ray diffraction, atomic force microscopy and scanning electron microscopy. It shows that the deposited material does not uniformly fill the porous volume of the anodic alumina film and the part of it forms a thick layer on the PAA surface. The aim of this work is to show the differences in the XRD response obtained at different angles of incidence of the excitation beam for the PAA/YAlO3:Tb3+ system. Furthermore, this simple approach enables separation of the signal from both regions on the surface and inside the PAA pores, providing more accurate data interpretation. It reveals that the crystallization of the material on the PAA surface and within the pores is different.
Journal of Electrical Engineering, 2014
GaInNAs alloys are mostly used as an active part of light sources for long wavelength telecom app... more GaInNAs alloys are mostly used as an active part of light sources for long wavelength telecom applications. Beside this, these materials are used as thin quantum wells (QWs), and a need is to grow thick layers of such semiconductor alloys for photodetectors and photovoltaic cells applications. However, structural characterization of the GaInNAs layers is hindered by non-homogeneity of the In and N distributions along the layer. In this work the challenges of the structural characterization of doped thick GaInNAs layers grown by atmospheric pressure metalorganic vapour phase epitaxy (APMOVPE) will be presented
Opto-Electronics Review, 2008
The nitrogen-containing conventional AIIIBV semiconductor alloys, so-called diluted nitrides (AII... more The nitrogen-containing conventional AIIIBV semiconductor alloys, so-called diluted nitrides (AIIIBV-N), have been extensively studied recently. Unusual properties of these materials make them very promising for applications in lasers and very efficient multijunction solar cells. This work presents the technology and properties of undoped GaAs1-xNx/GaAs heterostructures used as active regions in the construction of metal-semiconductor-metal (MSM) photodetectors. The atmospheric pressure metal organic vapour phase epitaxy (APMOVPE) was applied for growing MSM test structures. Their structural and optical properties were examined using high resolution X-ray diffraction (HRXRD), photoluminescence (PL), and photoreflectance spectroscopy (PR). Chemical wet etching was applied for forming an active region and a multifinger Schottky metallization was used as MSM contacts. Dark and illuminated current-voltage characteristics were measured. Based on the obtained results, the main detector pa...
Journal of The Electrochemical Society, 2010
Terbium-doped yttrium-aluminum oxide films were synthesized by spin-on deposition on porous anodi... more Terbium-doped yttrium-aluminum oxide films were synthesized by spin-on deposition on porous anodic alumina grown on a silicon wafer and annealed from 400 to 1100°C. An influence of the annealing temperature on the terbium photoluminescence ͑PL͒ was studied using two-dimensional PL excitation and time-resolved spectroscopy. Further, a comparison of thermal quenching data for the most intensive 5 D 4 → 7 F 5 luminescence band of Tb 3+ ions was performed for 10-300 K. From the resultant data, the mechanisms of Tb excitation and its dependence on the annealing conditions are proposed and discussed.
Materials Science in Semiconductor Processing
Acta Physica Polonica A
The structural properties of AlGaN layers deposited on high-and low-temperature grown AlN buffer ... more The structural properties of AlGaN layers deposited on high-and low-temperature grown AlN buffer were analysed. Modulated ammonia flow method of preparing AlN buffer was compared with a constant ammonia flow process using metalorganic vapour phase epitaxy. Low-temperature growth of the AlN buffer led to an increase of surface roughness, nevertheless crystal quality was comparable to the AlN buffer grown in high-temperature. Low-temperature nucleation AlN on sapphire substrates was required due to differences in thermal expansion and possible reduction of the number of dislocation. Modulated ammonia flow method provides an alternative approach for the AlN buffer growth at reduced reactor temperature.
Journal of Applied Physics
Selection of a suitable chemical etching method for threading dislocations density estimation is ... more Selection of a suitable chemical etching method for threading dislocations density estimation is crucial for the structural characterization of epilayers grown by MOVPE and thus further for device fabrication. In this work, threading dislocations density in single layer and Al x Ga 1Àx N/GaN periodical heterostructures has been investigated by means of chemical etching and XRD analysis. For chemical etching, two types of agents have been used: phosphoric acid (220 C=7:5 min) and a molten mixture of KOH-NaOH (440 C=2:5 min). Estimation of dislocation density has been carried out on the basis of SEM images. It was shown that defect-selective etching in molten alkaline solution is more effective than etching in phosphoric acid and provides more accurate data that are in agreement with data obtained from XRD characterization.
Advances in Electrical and Electronic Engineering
In this work, the thermal synthesis and characterization of gallium oxide and indium oxide nanowi... more In this work, the thermal synthesis and characterization of gallium oxide and indium oxide nanowires using vapour-liquid-solid mechanism at atmospheric pressure were described. Au nanoislands formed by the solid-state dewetting process of various thickness metal layer were applied as growth catalyst of nanowires while high-purity metal reactants (In, Ga) were applied as AIII precursors. The catalytic layer thickness influence on the morphology of investigated nanostructures was studied. Material composition and structural properties were used for crystallographic quality of AIII-oxide nanowires examination.
Materials Science-Poland
An attempt has been undertaken to produce gallium oxide nanowires by thermal synthesis from metal... more An attempt has been undertaken to produce gallium oxide nanowires by thermal synthesis from metallic gallium source at atmospheric pressure. Silicon substrates of (1 0 0) and (1 1 1) orientation with and without silicon oxide layers (0.5 μm) were used as support. Evaporated thin gold films were deposited on the top of those silicon carriers as a catalytic agent. After thermal treatment by Rapid Thermal Processing RTP (at various temperatures and times), which was applied to make small Au islands with the diameters of about several tens of nanometers, the substrate surfaces were observed by SEM. The Ga
Applied Physics Letters, 2008
Elektronika Konstrukcje Technologie Zastosowania, 2008
Journal of Crystal Growth, 2015
This paper presents advantages of employing the wavelet method in X-ray high-resolution image ana... more This paper presents advantages of employing the wavelet method in X-ray high-resolution image analysis of nanostructures. It is shown that many more details of the structure examined can be distin- guished in rocking curves (RC) as well as in reciprocal space maps (RSM) after application of the numerical procedure. The method proposed seems to be particularly suitable for imperfect epitaxial layers having significant lattice mismatch with respect to substrate. By means of the wavelet analysis of the X-ray images using de-noising procedure details invisible in raw pictures can be detected such as thickness fringes, gradient of lattice parameters etc., and duration of measurements can be shortened.
X-ray reflectivity (XRR) is one of the primary measurement techniques for thickness calculation o... more X-ray reflectivity (XRR) is one of the primary measurement techniques for thickness calculation of thin films and multilayer period determination. This technique can also be used for the analysis of organic thin film multilayer structures. In this method, the accuracy of thickness calculation depends on precision of the determination of the local maxima of XRR curve. The analysis of the XRR curves is cumbersome because of the noise which is recorded while measurement. It can be improved using computer data analysis algorithms for noise reduction and determination of the local maxima on the XRR curve. One of such algorithms, widely used in the data spectroscopy analysis, is Savitzky–Golay (S–G) algorithm. In this paper, the application of S–G algorithm for thickness determination of self-assembled ion liquid nanolayer of dimethyldiallylammonium chloride (PDDA) is shown.
Properties of dilute nitrides material system like large discontinuity of a conduction band (due ... more Properties of dilute nitrides material system like large discontinuity of a conduction band (due to high electronegativity of nitrogen) [1], large band gap bowing coefficient [2], increased electron effective mass [3], large scattering rate (connected with a small radius of nitrogen atom in comparison with the others V group atoms) [4] provide a way to novel applications: telecommunications lasers [1], heterojunction bipolar transistors [5] and very efficient solar cells [6]. InGaAsN is a very promising, lattice matched to GaAs and In0.5Ga0.5P material with band gap about 1 eV. The control of indium and nitrogen amounts in the InGaAsN quaternary alloy offers the ability to tailor the value of band gap and positions of valence and conduction band edges. Main advantage of dilute nitrides is a large reduction of band gap caused by nitrogen introduction (about ~150 meV/% of N). The technology of GaAs is better developed and still much cheaper than indium phosphide and allow to fabricate...
2007 International Students and Young Scientists Workshop on Photonics and Microsystems, 2007
High temperature gallium nitride (HT-GaN) layers were grown by HVPE (hydride vapor phase epitaxy)... more High temperature gallium nitride (HT-GaN) layers were grown by HVPE (hydride vapor phase epitaxy) method on low temperature GaN (LT-GaN) buffer layers deposited by HVPE or MOVPE method and on double MOVPE LT-GaN/AIN buffers. The (0001) sapphire substrates were applied. The HCl flow rate and deposition time intervals of nucleation layer deposition were varied in the range of 8-10 ml/min