Pub Date : 2022-09-30DOI: 10.3390/electronicmat3040025
W. Hourani, C. Rousselot, Kouamé Boko Joël-Igor N’Djoré, A. Billard, M. Arab Pour Yazdi, Y. Makoudi
Lanthanum manganite (LMO) thin films were deposited by co-sputtering La and Mn targets in an Ar and O2 gas mixture. The films were synthesized on silicon and fused silica substrates. The influences of thermal annealing on the structure, optical and electrical properties of LMO films were investigated. The results exhibited a correlation between these properties. In the amorphous state, an increase in annealing temperature improved the optical transmission and decreased the electrical capacitance. The beginning of crystallization at 600 °C was manifested by a strong increase in the capacitance and a decrease in the optical transmission. At higher annealing temperature, polycrystalline films were obtained with different optical and electrical characteristics. On the other hand, the annealed LMO films showed a photocurrent effect during exposure to a weak LED light.
{"title":"Thermal Annealing Effect on the Structure, Optical and Electrical Properties of Lanthanum Manganite Thin Films Prepared by Reactive Co-Sputtering","authors":"W. Hourani, C. Rousselot, Kouamé Boko Joël-Igor N’Djoré, A. Billard, M. Arab Pour Yazdi, Y. Makoudi","doi":"10.3390/electronicmat3040025","DOIUrl":"https://doi.org/10.3390/electronicmat3040025","url":null,"abstract":"Lanthanum manganite (LMO) thin films were deposited by co-sputtering La and Mn targets in an Ar and O2 gas mixture. The films were synthesized on silicon and fused silica substrates. The influences of thermal annealing on the structure, optical and electrical properties of LMO films were investigated. The results exhibited a correlation between these properties. In the amorphous state, an increase in annealing temperature improved the optical transmission and decreased the electrical capacitance. The beginning of crystallization at 600 °C was manifested by a strong increase in the capacitance and a decrease in the optical transmission. At higher annealing temperature, polycrystalline films were obtained with different optical and electrical characteristics. On the other hand, the annealed LMO films showed a photocurrent effect during exposure to a weak LED light.","PeriodicalId":18610,"journal":{"name":"Modern Electronic Materials","volume":"72 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76028465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-27DOI: 10.3390/electronicmat3040024
Nicolò Lago, Marco Buonomo, F. Prescimone, S. Toffanin, M. Muccini, A. Cester
Among the plethora of soluble and easy processable organic semiconductors, 6,13-Bis(triisopropylsilylethynyl)pentacene (TIPS-P5) is one of the most promising materials for next-generation flexible electronics. However, based on the information reported in the literature, it is difficult to exploit in field-effect transistors the high-performance characteristics of this material. This article correlates the HMDS functionalization of the silicon substrate with the electrical characteristics of TIPS-P5-based bottom gate organic field-effect transistors (OFETs) and electrolyte-gated organic field-effect transistors (EGOFETs) fabricated over the same platform. TIPS-P5 transistors with a double-gate architecture were fabricated by simple drop-casting on Si/SiO2 substrates, and the substrates were either functionalized with hexamethyldisilazane (HMDS) or left untreated. The same devices were characterized both as standard bottom-gate transistors and as (top-gate) electrolyte-gated transistors, and the results with and without HMDS treatment were compared. It is shown that the functionalization of the silicon substrate negatively influences EGOFETs performance, while it is beneficial for bottom-gate OFETs. Different device architectures (e.g., bottom-gate vs. top-gate) require specific evaluation of the fabrication protocols starting from the effect of the HMDS functionalization to maximize the electrical characteristics of TIPS-P5-based devices.
{"title":"Direct Comparison of the Effect of Processing Conditions in Electrolyte-Gated and Bottom-Gated TIPS-Pentacene Transistors","authors":"Nicolò Lago, Marco Buonomo, F. Prescimone, S. Toffanin, M. Muccini, A. Cester","doi":"10.3390/electronicmat3040024","DOIUrl":"https://doi.org/10.3390/electronicmat3040024","url":null,"abstract":"Among the plethora of soluble and easy processable organic semiconductors, 6,13-Bis(triisopropylsilylethynyl)pentacene (TIPS-P5) is one of the most promising materials for next-generation flexible electronics. However, based on the information reported in the literature, it is difficult to exploit in field-effect transistors the high-performance characteristics of this material. This article correlates the HMDS functionalization of the silicon substrate with the electrical characteristics of TIPS-P5-based bottom gate organic field-effect transistors (OFETs) and electrolyte-gated organic field-effect transistors (EGOFETs) fabricated over the same platform. TIPS-P5 transistors with a double-gate architecture were fabricated by simple drop-casting on Si/SiO2 substrates, and the substrates were either functionalized with hexamethyldisilazane (HMDS) or left untreated. The same devices were characterized both as standard bottom-gate transistors and as (top-gate) electrolyte-gated transistors, and the results with and without HMDS treatment were compared. It is shown that the functionalization of the silicon substrate negatively influences EGOFETs performance, while it is beneficial for bottom-gate OFETs. Different device architectures (e.g., bottom-gate vs. top-gate) require specific evaluation of the fabrication protocols starting from the effect of the HMDS functionalization to maximize the electrical characteristics of TIPS-P5-based devices.","PeriodicalId":18610,"journal":{"name":"Modern Electronic Materials","volume":"24 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83327568","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-26DOI: 10.3390/electronicmat3040023
Bruna Cruz, P. Eschlwech, Michael Hani, Erwin M. Biebl
The use of nonmetallic conductor materials in RF applications has recently become a highlighted issue when it comes to sustainability in the electronics industry, mainly because of the waste problems associated with heavy metals and the necessity of reducing and managing them. The replacement of metal in functional applications such as in electronics is therefore very important. Among these new materials, organic conductors are of great interest since they are, in general, biocompatible and biodegradable, allowing for the disposal of electronic devices, which reduces the negative environment impact caused by electronics waste. In this work, PEDOT:PSS and Carbon are investigated. Since these materials are available as conducting pastes or inks, the production of conducting patterns by printing techniques such as screen printing is possible, which can make the process less harmful to the environment, since it permits the use of organic substrates such as paper. In order to investigate the feasibility of these materials for RF signal transmission, screen printed PEDOT:PSS and Carbon transmission lines have been designed, fabricated and characterized. Results regarding conductivity, thickness, electric permittivity and S21 parameter are presented and will serve as a foundation for the development of further reaching applications utilizing organic materials.
{"title":"Characterization of Organic Conductive Materials as an Ecological Solution for RF Applications","authors":"Bruna Cruz, P. Eschlwech, Michael Hani, Erwin M. Biebl","doi":"10.3390/electronicmat3040023","DOIUrl":"https://doi.org/10.3390/electronicmat3040023","url":null,"abstract":"The use of nonmetallic conductor materials in RF applications has recently become a highlighted issue when it comes to sustainability in the electronics industry, mainly because of the waste problems associated with heavy metals and the necessity of reducing and managing them. The replacement of metal in functional applications such as in electronics is therefore very important. Among these new materials, organic conductors are of great interest since they are, in general, biocompatible and biodegradable, allowing for the disposal of electronic devices, which reduces the negative environment impact caused by electronics waste. In this work, PEDOT:PSS and Carbon are investigated. Since these materials are available as conducting pastes or inks, the production of conducting patterns by printing techniques such as screen printing is possible, which can make the process less harmful to the environment, since it permits the use of organic substrates such as paper. In order to investigate the feasibility of these materials for RF signal transmission, screen printed PEDOT:PSS and Carbon transmission lines have been designed, fabricated and characterized. Results regarding conductivity, thickness, electric permittivity and S21 parameter are presented and will serve as a foundation for the development of further reaching applications utilizing organic materials.","PeriodicalId":18610,"journal":{"name":"Modern Electronic Materials","volume":"26 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82719837","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-09-14DOI: 10.3390/electronicmat3030022
W. Pisula
Electronic materials are of great interest due to their potential to be applied in a broad range of important electronic devices including transistors, sensors, solar cells and others [...]
电子材料因其广泛应用于晶体管、传感器、太阳能电池等重要电子器件的潜力而备受关注。
{"title":"Characterization of Electronic Materials","authors":"W. Pisula","doi":"10.3390/electronicmat3030022","DOIUrl":"https://doi.org/10.3390/electronicmat3030022","url":null,"abstract":"Electronic materials are of great interest due to their potential to be applied in a broad range of important electronic devices including transistors, sensors, solar cells and others [...]","PeriodicalId":18610,"journal":{"name":"Modern Electronic Materials","volume":"350 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-09-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79700945","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-19DOI: 10.3390/electronicmat3030021
Jong-Keun Choi, Young-Gyun Kim, K. Han
Currently, as the next-generation of display progresses—with high performance and high integration—the surface mounting technology of components is very important. In particular, in the case of flexible displays, such as rollable and bendable displays, ACF that connects wires to any curvature is essential. However, the conductive ball used inside the ACF has had problems with particle size and non-uniform metal coating. It was confirmed that the presence of solvent and oxygen, which are used in polymer synthesis, affects the sphere formation of polymer beads. By optimizing the factors affecting the polymer beads, a perfect spherical polymer bead was manufactured. In addition, the conductive ball manufacturing process was optimized by confirming the factors affecting the metal coating. The metal coating on the surface of the polymer bead was applied with a uniform thickness by considering the specific surface area and concentration of the conductive balls, and, through this optimized process, conductive balls for anisotropic conductive films with uniform size and metal thickness were obtained.
{"title":"A Study on the Optimization of the Conductive Ball Manufacturing Process, Used for Anisotropic Conductive Films","authors":"Jong-Keun Choi, Young-Gyun Kim, K. Han","doi":"10.3390/electronicmat3030021","DOIUrl":"https://doi.org/10.3390/electronicmat3030021","url":null,"abstract":"Currently, as the next-generation of display progresses—with high performance and high integration—the surface mounting technology of components is very important. In particular, in the case of flexible displays, such as rollable and bendable displays, ACF that connects wires to any curvature is essential. However, the conductive ball used inside the ACF has had problems with particle size and non-uniform metal coating. It was confirmed that the presence of solvent and oxygen, which are used in polymer synthesis, affects the sphere formation of polymer beads. By optimizing the factors affecting the polymer beads, a perfect spherical polymer bead was manufactured. In addition, the conductive ball manufacturing process was optimized by confirming the factors affecting the metal coating. The metal coating on the surface of the polymer bead was applied with a uniform thickness by considering the specific surface area and concentration of the conductive balls, and, through this optimized process, conductive balls for anisotropic conductive films with uniform size and metal thickness were obtained.","PeriodicalId":18610,"journal":{"name":"Modern Electronic Materials","volume":"54 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91161936","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-08-03DOI: 10.3390/electronicmat3030020
Samiul Hasan, Iftikhar Ahmad
This article will briefly review the progress of h-BN based solid-state metal semiconductor metal (MSM) neutron detectors. In the last decade, several groups have been working on hexagonal boron nitride (h-BN)-based solid-state neutron detectors. Recently, the detection efficiency of 59% has been reported. Efficient, low-cost neutron detectors made from readily available materials are essential for various applications. Neutron detectors are widely used to detect fissile materials and nuclear power plants for security applications. The most common and widely used neutron detectors are 3He based, which are sometimes bulky, difficult to transport, have high absorption length, need relatively high bias voltage (>1000 V), and have low Q-value (0.764 MeV). In addition, 3He is not a readily available material. Thus, there is a strong need to find an alternative detection material. The 10B isotope has a high neutron absorption cross-section, and it has been tested as a coating on the semiconducting materials. Due to the two-step process, neutron capture through 10B and then electron–hole pair generation in a typical semiconducting material, the efficiency of these devices is not up to the mark. The progress in h-BN based detectors requires a review to envision the further improvement in this technology.
{"title":"Progress in Hexagonal Boron Nitride (h-BN)-Based Solid-State Neutron Detector","authors":"Samiul Hasan, Iftikhar Ahmad","doi":"10.3390/electronicmat3030020","DOIUrl":"https://doi.org/10.3390/electronicmat3030020","url":null,"abstract":"This article will briefly review the progress of h-BN based solid-state metal semiconductor metal (MSM) neutron detectors. In the last decade, several groups have been working on hexagonal boron nitride (h-BN)-based solid-state neutron detectors. Recently, the detection efficiency of 59% has been reported. Efficient, low-cost neutron detectors made from readily available materials are essential for various applications. Neutron detectors are widely used to detect fissile materials and nuclear power plants for security applications. The most common and widely used neutron detectors are 3He based, which are sometimes bulky, difficult to transport, have high absorption length, need relatively high bias voltage (>1000 V), and have low Q-value (0.764 MeV). In addition, 3He is not a readily available material. Thus, there is a strong need to find an alternative detection material. The 10B isotope has a high neutron absorption cross-section, and it has been tested as a coating on the semiconducting materials. Due to the two-step process, neutron capture through 10B and then electron–hole pair generation in a typical semiconducting material, the efficiency of these devices is not up to the mark. The progress in h-BN based detectors requires a review to envision the further improvement in this technology.","PeriodicalId":18610,"journal":{"name":"Modern Electronic Materials","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73233508","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-07-28DOI: 10.3390/electronicmat3030019
G. Suchaneck
This work presents an examination and unification of fragmented data on spin polarization in half-metallic, ferrimagnetic oxides. It also includes well understood ferromagnetic metals for comparison. The temperature and disorder dependencies of the spin polarization are evaluated. Both the temperature dependence of the tunnel magnetoresistance and, for the very first time, its temperature coefficient are calculated based on the simplified Julliére model. The tunnel magnetoresistance in the magnetic tunnel junctions deteriorates due to the temperature dependence of the spin polarization the lower the Curie temperature is. As a result, magnetic tunnel junctions—consisting of ferromagnetic oxides with a Curie temperature not far above room temperature—are not promising for room temperature applications. Additionally, ferrimagnetic oxides possessing a Curie temperature below 650 K are not suitable for room temperature applications because of an unacceptable temperature coefficient exceeding −2%.
{"title":"Tunnel Spin-Polarization of Ferromagnetic Metals and Ferrimagnetic Oxides and Its Effect on Tunnel Magnetoresistance","authors":"G. Suchaneck","doi":"10.3390/electronicmat3030019","DOIUrl":"https://doi.org/10.3390/electronicmat3030019","url":null,"abstract":"This work presents an examination and unification of fragmented data on spin polarization in half-metallic, ferrimagnetic oxides. It also includes well understood ferromagnetic metals for comparison. The temperature and disorder dependencies of the spin polarization are evaluated. Both the temperature dependence of the tunnel magnetoresistance and, for the very first time, its temperature coefficient are calculated based on the simplified Julliére model. The tunnel magnetoresistance in the magnetic tunnel junctions deteriorates due to the temperature dependence of the spin polarization the lower the Curie temperature is. As a result, magnetic tunnel junctions—consisting of ferromagnetic oxides with a Curie temperature not far above room temperature—are not promising for room temperature applications. Additionally, ferrimagnetic oxides possessing a Curie temperature below 650 K are not suitable for room temperature applications because of an unacceptable temperature coefficient exceeding −2%.","PeriodicalId":18610,"journal":{"name":"Modern Electronic Materials","volume":"77 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-07-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91542344","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-30DOI: 10.3897/j.moem.8.2.90174
S. Kobeleva
A method has been suggested for determining stoichiometry deviation in cadmium and zinc chalcogenides based on the temperature dependence of the ratio of components partial pressures during evaporation of solid compounds in a limited volume. The new method differs from methods implying the collection of excessive component during evaporation in large volumes. The method includes measuring the partial pressures of vapor phase components during material heating to above 800 K, solving a set of material balance equations and the electric neutrality equation, and calculating the stoichiometry deviation in the initial compound at room temperature. Intrinsic point defect concentrations are calculated using the method of quasichemical reactions. The independent variables in the set of material balance equations are the sought stoichiometry deviation, the partial pressure of the metal and the concentration of free electrons. We show that the parameter of the material balance equation which determines the method’s sensitivity to stoichiometry deviation, i.e., the volume ratio of vapor and solid phases, can be considered constant during heating and evaporation if this parameter does not exceed 50. If the partial pressure is measured based on the optical density of the vapors, then the sensitivity of the method can be increased to not worse than 10–6 at.%.
{"title":"Determination of stoichiometry deviation in wide-band II–VI semiconductors on the basis of equilibrium vapor phase composition","authors":"S. Kobeleva","doi":"10.3897/j.moem.8.2.90174","DOIUrl":"https://doi.org/10.3897/j.moem.8.2.90174","url":null,"abstract":"A method has been suggested for determining stoichiometry deviation in cadmium and zinc chalcogenides based on the temperature dependence of the ratio of components partial pressures during evaporation of solid compounds in a limited volume. The new method differs from methods implying the collection of excessive component during evaporation in large volumes. The method includes measuring the partial pressures of vapor phase components during material heating to above 800 K, solving a set of material balance equations and the electric neutrality equation, and calculating the stoichiometry deviation in the initial compound at room temperature. Intrinsic point defect concentrations are calculated using the method of quasichemical reactions. The independent variables in the set of material balance equations are the sought stoichiometry deviation, the partial pressure of the metal and the concentration of free electrons. We show that the parameter of the material balance equation which determines the method’s sensitivity to stoichiometry deviation, i.e., the volume ratio of vapor and solid phases, can be considered constant during heating and evaporation if this parameter does not exceed 50. If the partial pressure is measured based on the optical density of the vapors, then the sensitivity of the method can be increased to not worse than 10–6 at.%.","PeriodicalId":18610,"journal":{"name":"Modern Electronic Materials","volume":"8 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73443629","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-30DOI: 10.3897/j.moem.8.2.90062
S. Tokmoldin, V. V. Klimenov, D. V. Girin, N. Chuchvaga, K. Aimaganbetov, M. P. Kishkenebaev, S. N. Tarakanova, N. Tokmoldin
Mathematical simulation of temperature distribution on double-sided solar cells has been carried out. Differences in the configuration of photoelectric converters prove to solely amount to the fact that a double-sided solar cell has a more efficient heat sink at the rear side. Furthermore double-sided solar cells exhibit higher power conversion performance. Calculations confirm the correctness of giving preference to double-sided solar cells which is of great importance for the photoelectric converter design developed by us. Analysis of market-available photovoltaic technologies of solar energy to electric power conversion has led to the development of a photovoltaic converter on the basis of double-sided silicon heterojunction solar cells. The configuration developed is a moving platform having a photovoltaic cell array mounted on it and a light flux collector. A double-axis tracking system has been developed for the general case of planar attachment of solar cell modules. A 350 mm stroke drive provides for movement in the north-south direction and a 450 mm stroke drive, in the east-west direction. The task has been outlined to find the required arm for providing symmetrical positioning at the maximum rotation angle about the axis. As a result, technical solutions have been developed for the north-south and the east-west directions. Furthermore a schematic wiring diagram has been designed to implement the preset solar tracking system algorithm. The system is also fitted with a GPS/GLONASS module for system precision positioning and time synchronization.
{"title":"Development of a mobile independent solar power plant based on solid-state heterojunction photocells for agricultural purposes","authors":"S. Tokmoldin, V. V. Klimenov, D. V. Girin, N. Chuchvaga, K. Aimaganbetov, M. P. Kishkenebaev, S. N. Tarakanova, N. Tokmoldin","doi":"10.3897/j.moem.8.2.90062","DOIUrl":"https://doi.org/10.3897/j.moem.8.2.90062","url":null,"abstract":"Mathematical simulation of temperature distribution on double-sided solar cells has been carried out. Differences in the configuration of photoelectric converters prove to solely amount to the fact that a double-sided solar cell has a more efficient heat sink at the rear side. Furthermore double-sided solar cells exhibit higher power conversion performance. Calculations confirm the correctness of giving preference to double-sided solar cells which is of great importance for the photoelectric converter design developed by us. Analysis of market-available photovoltaic technologies of solar energy to electric power conversion has led to the development of a photovoltaic converter on the basis of double-sided silicon heterojunction solar cells. The configuration developed is a moving platform having a photovoltaic cell array mounted on it and a light flux collector.\u0000 A double-axis tracking system has been developed for the general case of planar attachment of solar cell modules. A 350 mm stroke drive provides for movement in the north-south direction and a 450 mm stroke drive, in the east-west direction. The task has been outlined to find the required arm for providing symmetrical positioning at the maximum rotation angle about the axis. As a result, technical solutions have been developed for the north-south and the east-west directions.\u0000 Furthermore a schematic wiring diagram has been designed to implement the preset solar tracking system algorithm. The system is also fitted with a GPS/GLONASS module for system precision positioning and time synchronization.","PeriodicalId":18610,"journal":{"name":"Modern Electronic Materials","volume":"29 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85632607","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2022-06-22DOI: 10.3390/electronicmat3030018
L. Florencio, J. Luzardo, M.M.S. Pojucan, Victor Cunha, Alexander Silva, R. Valaski, Joyce Araujo
In this work, the electrical properties of graphene papers were investigated with the aim of developing pressure sensor prototypes for measuring pressures up to 2 kPa. In order to determine which graphene paper would be the most suitable, three different types of graphene papers, synthesized by different routes, were prepared and electrically characterized. The results of electrical characterizations, in terms of electrical conductivity and sheet resistance of graphene papers, are presented and discussed. Prototypes of pressure sensors are proposed, using graphene papers obtained by chemical oxidation (graphene oxide and reduced graphene oxide) and by electrochemical exfoliation. The prototypes were tested in static compression/decompression tests in the working range of 0 kPa to 1.998 kPa. The compression/decompression sensitivity values observed in these prototype sensors ranged from 20.8% ΔR/kPa for graphene sensors obtained by electrochemical exfoliation to 110.7% ΔR/kPa for those prepared from graphene oxide obtained by chemical oxidation. More expressive sensitivity values were observed for the sensors fabricated from GO, intermediate values for those made of rGO, while prototypes made of EG showed lower sensitivity.
{"title":"Prototyping and Evaluation of Graphene-Based Piezoresistive Sensors","authors":"L. Florencio, J. Luzardo, M.M.S. Pojucan, Victor Cunha, Alexander Silva, R. Valaski, Joyce Araujo","doi":"10.3390/electronicmat3030018","DOIUrl":"https://doi.org/10.3390/electronicmat3030018","url":null,"abstract":"In this work, the electrical properties of graphene papers were investigated with the aim of developing pressure sensor prototypes for measuring pressures up to 2 kPa. In order to determine which graphene paper would be the most suitable, three different types of graphene papers, synthesized by different routes, were prepared and electrically characterized. The results of electrical characterizations, in terms of electrical conductivity and sheet resistance of graphene papers, are presented and discussed. Prototypes of pressure sensors are proposed, using graphene papers obtained by chemical oxidation (graphene oxide and reduced graphene oxide) and by electrochemical exfoliation. The prototypes were tested in static compression/decompression tests in the working range of 0 kPa to 1.998 kPa. The compression/decompression sensitivity values observed in these prototype sensors ranged from 20.8% ΔR/kPa for graphene sensors obtained by electrochemical exfoliation to 110.7% ΔR/kPa for those prepared from graphene oxide obtained by chemical oxidation. More expressive sensitivity values were observed for the sensors fabricated from GO, intermediate values for those made of rGO, while prototypes made of EG showed lower sensitivity.","PeriodicalId":18610,"journal":{"name":"Modern Electronic Materials","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2022-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90929469","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}