In recent work, heat-technical modeling, life cycle assessment, and rehabilitation of the vernacu... more In recent work, heat-technical modeling, life cycle assessment, and rehabilitation of the vernacular adobe wall house is discussed. Our topic choice is based on the fact that a significant part of the Hungarian rural housing stock consist of adobe-walled buildings. The adobe wall construction is especially perfect for the seasonal climatic equalizing, which property has increasing ecological importance due to the effect of growing global warming up. Largely, these adobe-walled houses are part of our cultural heritage, therefore they are worth to preserving. Finally, their constructional conservation, energetical rehabilitation and also maintenance problems are briefly described..
American journal of condensed matter physics, 2017
A model of filling dynamics of nanoholes will be detailed in this paper. The filling material wil... more A model of filling dynamics of nanoholes will be detailed in this paper. The filling material will be modelled as a viscous liquid. The structure of this paper is as follows. The forming of nanoholes will be briefly described and the filling of these nanoholes will be detailed with and without surface diffusion. The modelling algorithm will be shown for InAs / InGaAs substrate. The description of the modelling algorithm, one possible microscopic interpretation of the viscosity will studied as well. In addition, the number of layers and the equilibrium height relation will be investigated at different temperatures. Furthermore both the viscosity and equilibrium height will be investigated as the function of the temperature. Out investigations will be carried out at macroscopical and microscopical levels as well.
2021 IEEE 4th International Conference and Workshop Óbuda on Electrical and Power Engineering (CANDO-EPE), 2021
The present work is based on a database, which has been created by us on III-V compound semicondu... more The present work is based on a database, which has been created by us on III-V compound semiconductor-based droplet-epitaxially grown zero dimensional nanostructures. Principal component analysis (PCA) has been carried out on different sets of variables. PCA is best illustrated by matching a multidimensional ellipsoid onto the observation “cloud”. Generally, the magnitudes of projections of principal components onto parameter axes reflect well the importance of the given variable. Kohonen Self-Organizing Mapping was carried out on the projection of 9D data onto the plane of the first two principal components. Clustering have been observed.
2021 IEEE 4th International Conference and Workshop Óbuda on Electrical and Power Engineering (CANDO-EPE), 2021
A literature-based database has been created by us on III-V composite semiconductor-based droplet... more A literature-based database has been created by us on III-V composite semiconductor-based droplet epitaxially grown zero dimensional nanostructures. Linear regression models have been specified on logarithms of database parameters in order to enable droplet epitaxial technique users to design approximate geometric dimensions of zero dimensional nanostructures. Using logarithms essentially leads to a multiplicative model, the dependent variable is obtained as a product of given powers of the independent variables. Both structure diameters and structure heights have been well estimated by the multiplicative model.
With the help of the different nanostructures novel semiconductor devices can be produced or the ... more With the help of the different nanostructures novel semiconductor devices can be produced or the parameters of the currently applied traditional devices can be improved in a significant manner also. The inverted quantum dots are belongs to this group. During the production of these nanostructures, fnanoholes are formed and filled. In our previous investigations, the formation of these nanostructures was modelled by an empirical modell, with the consideration of the microscopical viscosity of the melted metals. In this article a detailed discussion of thi modell is given, in case of the aluminium. Kivonat Kulonboző nanoszerkezetek segitsegevel ujfajta felvezető eszkozoket keszithetunk, vagy a jelenleg alkalmazott eszkozok parametereit is jelentős mertekben javitani tudjuk. Ide tartozik az ugynevezett invertalt kvantum pontok csoportja is. Ennek az előallitasi modja az, hogy előszor egy nanolyukat keszitunk, majd ezt a lyukat betemetjuk. Korabbi kutatasunkban e nanoszerkezetek kialaku...
It is well known, that the light emitting (radiative recombination and electroluminescence) and a... more It is well known, that the light emitting (radiative recombination and electroluminescence) and absorbing processes need special material properties and conditions. One of these fundamental conditions, is the direct band transition of the semiconductor material. This is a common property among the compound semiconductors. The production technology of devices significantly different from the ordinary silicon technology. In the creation of the device structure, the epitaxial growth plays an important role, during which similar crystal structures like the substrate, but some other different characteristics layers have grown. There are various methods and technologies of the layer growing by epitaxy. The Molecular Beam Epitaxy (MBE) stands out among the other procedures, because this is the most sophisticated and the most effective technique for the production of zero, one and two dimensional nanostructures. These semiconductor devices are revolutionized by these structures, including the light emission diodes and solar cells as well. In this article we will give a short introduction of MBE technique, and discuss about light emission diodes and solar cells, produced by this method.
The present work is based on a database, which has been created by us on III-V compound semicondu... more The present work is based on a database, which has been created by us on III-V compound semiconductorbased droplet-epitaxially grown zero dimensional nanostructures. Principal component analysis (PCA) has been carried out on different sets of variables. PCA is best illustrated by matching a multidimensional ellipsoid onto the observation "cloud". Generally, the magnitudes of projections of principal components onto parameter axes reflect well the importance of the given variable. Kohonen Self-Organizing Mapping was carried out on the projection of 9D data onto the plane of the first two principal components. Clustering have been observed.
A literature-based database has been created by us on III-V composite semiconductor-based droplet... more A literature-based database has been created by us on III-V composite semiconductor-based droplet epitaxially grown zero dimensional nanostructures. Linear regression models have been specified on logarithms of database parameters in order to enable droplet epitaxial technique users to design approximate geometric dimensions of zero dimensional nanostructures. Using logarithms essentially leads to a multiplicative model, the dependent variable is obtained as a product of given powers of the independent variables. Both structure diameters and structure heights have been well estimated by the multiplicative model.
A literature-based database has been investigated in order to establish strategic roadmap for nan... more A literature-based database has been investigated in order to establish strategic roadmap for nanostructure technology. Practically this is carried out by finding relationship between technology parameters and geometric properties of nanostructures produced by droplet epitaxial process. The crucial point is to deal with high-dimensionality of both technological and geometrical parameters of nanostructures. Principal component analysis and regression were used. Geometrical parameters were substituted with analytical fitting ones. Soft computing methods were also applied to find abovementioned relationships.
The present work deals with contact problems of GaAs-based solar cells. In the introduction the m... more The present work deals with contact problems of GaAs-based solar cells. In the introduction the most basic GaAs-based solar cell structures are introduced. Then, the energy and electronic properties are investigated. In the third part of this publication, the technological aspects of the metallization are discussed. Here the surface patterns are investigated, that are formed at the surface of the Au/GaAs and Au/TiN/GaAs material systems, as the effect of the annealing process. The further aim of these investigations to investigate, how the properties of ohmic contact depends on the properties of the material system. If these relations are known, the relationships between different morphologies and their electric qualities will be also known.
2018 7th International Symposium on Next Generation Electronics (ISNE), 2018
In this work, we are dealing with a novel technology, called droplet epitaxy, which is useful tec... more In this work, we are dealing with a novel technology, called droplet epitaxy, which is useful technique when quantum dots are to be produced, of different shape and size in various densities. There are self-assembling methods to achieve quantum dot ensembles and their spatial ordering and positioning. Their evolution kinetic is very important to handheld the self-assembling. After the discussion of the growth mechanism, we are dealing some of self-assembled quantum dot arrangement in the view point of realization of nano-electronics.
In recent work, heat-technical modeling, life cycle assessment, and rehabilitation of the vernacu... more In recent work, heat-technical modeling, life cycle assessment, and rehabilitation of the vernacular adobe wall house is discussed. Our topic choice is based on the fact that a significant part of the Hungarian rural housing stock consist of adobe-walled buildings. The adobe wall construction is especially perfect for the seasonal climatic equalizing, which property has increasing ecological importance due to the effect of growing global warming up. Largely, these adobe-walled houses are part of our cultural heritage, therefore they are worth to preserving. Finally, their constructional conservation, energetical rehabilitation and also maintenance problems are briefly described..
American journal of condensed matter physics, 2017
A model of filling dynamics of nanoholes will be detailed in this paper. The filling material wil... more A model of filling dynamics of nanoholes will be detailed in this paper. The filling material will be modelled as a viscous liquid. The structure of this paper is as follows. The forming of nanoholes will be briefly described and the filling of these nanoholes will be detailed with and without surface diffusion. The modelling algorithm will be shown for InAs / InGaAs substrate. The description of the modelling algorithm, one possible microscopic interpretation of the viscosity will studied as well. In addition, the number of layers and the equilibrium height relation will be investigated at different temperatures. Furthermore both the viscosity and equilibrium height will be investigated as the function of the temperature. Out investigations will be carried out at macroscopical and microscopical levels as well.
2021 IEEE 4th International Conference and Workshop Óbuda on Electrical and Power Engineering (CANDO-EPE), 2021
The present work is based on a database, which has been created by us on III-V compound semicondu... more The present work is based on a database, which has been created by us on III-V compound semiconductor-based droplet-epitaxially grown zero dimensional nanostructures. Principal component analysis (PCA) has been carried out on different sets of variables. PCA is best illustrated by matching a multidimensional ellipsoid onto the observation “cloud”. Generally, the magnitudes of projections of principal components onto parameter axes reflect well the importance of the given variable. Kohonen Self-Organizing Mapping was carried out on the projection of 9D data onto the plane of the first two principal components. Clustering have been observed.
2021 IEEE 4th International Conference and Workshop Óbuda on Electrical and Power Engineering (CANDO-EPE), 2021
A literature-based database has been created by us on III-V composite semiconductor-based droplet... more A literature-based database has been created by us on III-V composite semiconductor-based droplet epitaxially grown zero dimensional nanostructures. Linear regression models have been specified on logarithms of database parameters in order to enable droplet epitaxial technique users to design approximate geometric dimensions of zero dimensional nanostructures. Using logarithms essentially leads to a multiplicative model, the dependent variable is obtained as a product of given powers of the independent variables. Both structure diameters and structure heights have been well estimated by the multiplicative model.
With the help of the different nanostructures novel semiconductor devices can be produced or the ... more With the help of the different nanostructures novel semiconductor devices can be produced or the parameters of the currently applied traditional devices can be improved in a significant manner also. The inverted quantum dots are belongs to this group. During the production of these nanostructures, fnanoholes are formed and filled. In our previous investigations, the formation of these nanostructures was modelled by an empirical modell, with the consideration of the microscopical viscosity of the melted metals. In this article a detailed discussion of thi modell is given, in case of the aluminium. Kivonat Kulonboző nanoszerkezetek segitsegevel ujfajta felvezető eszkozoket keszithetunk, vagy a jelenleg alkalmazott eszkozok parametereit is jelentős mertekben javitani tudjuk. Ide tartozik az ugynevezett invertalt kvantum pontok csoportja is. Ennek az előallitasi modja az, hogy előszor egy nanolyukat keszitunk, majd ezt a lyukat betemetjuk. Korabbi kutatasunkban e nanoszerkezetek kialaku...
It is well known, that the light emitting (radiative recombination and electroluminescence) and a... more It is well known, that the light emitting (radiative recombination and electroluminescence) and absorbing processes need special material properties and conditions. One of these fundamental conditions, is the direct band transition of the semiconductor material. This is a common property among the compound semiconductors. The production technology of devices significantly different from the ordinary silicon technology. In the creation of the device structure, the epitaxial growth plays an important role, during which similar crystal structures like the substrate, but some other different characteristics layers have grown. There are various methods and technologies of the layer growing by epitaxy. The Molecular Beam Epitaxy (MBE) stands out among the other procedures, because this is the most sophisticated and the most effective technique for the production of zero, one and two dimensional nanostructures. These semiconductor devices are revolutionized by these structures, including the light emission diodes and solar cells as well. In this article we will give a short introduction of MBE technique, and discuss about light emission diodes and solar cells, produced by this method.
The present work is based on a database, which has been created by us on III-V compound semicondu... more The present work is based on a database, which has been created by us on III-V compound semiconductorbased droplet-epitaxially grown zero dimensional nanostructures. Principal component analysis (PCA) has been carried out on different sets of variables. PCA is best illustrated by matching a multidimensional ellipsoid onto the observation "cloud". Generally, the magnitudes of projections of principal components onto parameter axes reflect well the importance of the given variable. Kohonen Self-Organizing Mapping was carried out on the projection of 9D data onto the plane of the first two principal components. Clustering have been observed.
A literature-based database has been created by us on III-V composite semiconductor-based droplet... more A literature-based database has been created by us on III-V composite semiconductor-based droplet epitaxially grown zero dimensional nanostructures. Linear regression models have been specified on logarithms of database parameters in order to enable droplet epitaxial technique users to design approximate geometric dimensions of zero dimensional nanostructures. Using logarithms essentially leads to a multiplicative model, the dependent variable is obtained as a product of given powers of the independent variables. Both structure diameters and structure heights have been well estimated by the multiplicative model.
A literature-based database has been investigated in order to establish strategic roadmap for nan... more A literature-based database has been investigated in order to establish strategic roadmap for nanostructure technology. Practically this is carried out by finding relationship between technology parameters and geometric properties of nanostructures produced by droplet epitaxial process. The crucial point is to deal with high-dimensionality of both technological and geometrical parameters of nanostructures. Principal component analysis and regression were used. Geometrical parameters were substituted with analytical fitting ones. Soft computing methods were also applied to find abovementioned relationships.
The present work deals with contact problems of GaAs-based solar cells. In the introduction the m... more The present work deals with contact problems of GaAs-based solar cells. In the introduction the most basic GaAs-based solar cell structures are introduced. Then, the energy and electronic properties are investigated. In the third part of this publication, the technological aspects of the metallization are discussed. Here the surface patterns are investigated, that are formed at the surface of the Au/GaAs and Au/TiN/GaAs material systems, as the effect of the annealing process. The further aim of these investigations to investigate, how the properties of ohmic contact depends on the properties of the material system. If these relations are known, the relationships between different morphologies and their electric qualities will be also known.
2018 7th International Symposium on Next Generation Electronics (ISNE), 2018
In this work, we are dealing with a novel technology, called droplet epitaxy, which is useful tec... more In this work, we are dealing with a novel technology, called droplet epitaxy, which is useful technique when quantum dots are to be produced, of different shape and size in various densities. There are self-assembling methods to achieve quantum dot ensembles and their spatial ordering and positioning. Their evolution kinetic is very important to handheld the self-assembling. After the discussion of the growth mechanism, we are dealing some of self-assembled quantum dot arrangement in the view point of realization of nano-electronics.
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Papers by Antal Ürmös