Present enquiry thoroughly explores the time‐average population transfer rate (TAPTR) of impurity doped GaAs quantum dot (QD) pursuing the change in the spatial impurity spread (SIS). The said excitation rate has been studied under the supervision of Gaussian white noise (GWN). The promotion of the ground state electronic density takes place due to different types of time‐changing fluctuations viz. simple sinusoidal field, time‐dependent confinement potential and time‐dependent magnetic field. GWN couples with the QD by additive and multiplicative modes. The work examines the joint influence of SIS, GWN and its pathway of inclusion and the nature of the time‐dependent perturbations on the attributes of the TAPTR. The TAPTR curves are composed of steadfast rise, steadfast diminish, maximization (relevant to generation of large nonlinear optical properties), minimization and saturation (suggesting dynamic freezing). The findings elucidate the means of fine‐tuning the TAPTR among the doped GaAs QD eigenstates in presence of noise, when the SIS undergoes a gradual change.This article is protected by copyright. All rights reserved.
{"title":"Role of spatial impurity spread on the transition dynamics of doped GaAs quantum dot in presence of noise","authors":"Swarnab Datta, Bhaskar Bhakti, M. Ghosh","doi":"10.1002/pssb.202300281","DOIUrl":"https://doi.org/10.1002/pssb.202300281","url":null,"abstract":"Present enquiry thoroughly explores the time‐average population transfer rate (TAPTR) of impurity doped GaAs quantum dot (QD) pursuing the change in the spatial impurity spread (SIS). The said excitation rate has been studied under the supervision of Gaussian white noise (GWN). The promotion of the ground state electronic density takes place due to different types of time‐changing fluctuations viz. simple sinusoidal field, time‐dependent confinement potential and time‐dependent magnetic field. GWN couples with the QD by additive and multiplicative modes. The work examines the joint influence of SIS, GWN and its pathway of inclusion and the nature of the time‐dependent perturbations on the attributes of the TAPTR. The TAPTR curves are composed of steadfast rise, steadfast diminish, maximization (relevant to generation of large nonlinear optical properties), minimization and saturation (suggesting dynamic freezing). The findings elucidate the means of fine‐tuning the TAPTR among the doped GaAs QD eigenstates in presence of noise, when the SIS undergoes a gradual change.This article is protected by copyright. All rights reserved.","PeriodicalId":20107,"journal":{"name":"physica status solidi (b)","volume":"50 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74437511","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}
Under vacuum environment, an H interstitial must exist when Ga2O3 is prepared by organometallic chemistry vapor deposition. However, few first‐principle systematic studies have been conducted on the influences of point vacancies (VGa, Hi) on the photocatalytic performance and magnetism of Ga2O3: Li or Na or K systems, and VGa is a challenge in experiments. Therefore, the first‐principle generalized gradient approximation GGA + U theory was adopted in this study. A first‐principle study was conducted on the formation energy (E f ), photocatalytic performance, and magnetism of Ga30MO48 (M = Li or Na, or K) and Ga30MHiO48 systems. Results show that under Ga‐poor conditions, the Ga30MO48 and Ga30MHiO48 systems are structurally stable and prone to doping. The Ga30MHiO48 system has lower E f , more structural stability, and easier doping than the Ga30MO48 system. The Ga30KO48 system exhibits magnetism, mainly generated by the O1−‐2p spin polarized wandering electrons near VGa. The spin polarized O2−‐2p and Ga‐4s states near VGa contribute to the hybrid coupling double‐exchange interaction. Moreover, the visible spectrum of the Ga30LiHiO48 system exhibits a significant red shift, a relatively high carrier activity, carrier separation, and relative maximum lifetime. It is relatively best as a photocatalyst.This article is protected by copyright. All rights reserved.
{"title":"First‐principle study of the influences of point vacancies (VGa, Hi) on the photocatalytic and magnetic performance of Ga2O3:Li/Na/K systems","authors":"Xuefei Bai, Q. Hou, Wencai Li, Mude Qi, Yulan Gu","doi":"10.1002/pssb.202300304","DOIUrl":"https://doi.org/10.1002/pssb.202300304","url":null,"abstract":"Under vacuum environment, an H interstitial must exist when Ga2O3 is prepared by organometallic chemistry vapor deposition. However, few first‐principle systematic studies have been conducted on the influences of point vacancies (VGa, Hi) on the photocatalytic performance and magnetism of Ga2O3: Li or Na or K systems, and VGa is a challenge in experiments. Therefore, the first‐principle generalized gradient approximation GGA + U theory was adopted in this study. A first‐principle study was conducted on the formation energy (E\u0000f\u0000), photocatalytic performance, and magnetism of Ga30MO48 (M = Li or Na, or K) and Ga30MHiO48 systems. Results show that under Ga‐poor conditions, the Ga30MO48 and Ga30MHiO48 systems are structurally stable and prone to doping. The Ga30MHiO48 system has lower E\u0000f\u0000, more structural stability, and easier doping than the Ga30MO48 system. The Ga30KO48 system exhibits magnetism, mainly generated by the O1−‐2p spin polarized wandering electrons near VGa. The spin polarized O2−‐2p and Ga‐4s states near VGa contribute to the hybrid coupling double‐exchange interaction. Moreover, the visible spectrum of the Ga30LiHiO48 system exhibits a significant red shift, a relatively high carrier activity, carrier separation, and relative maximum lifetime. It is relatively best as a photocatalyst.This article is protected by copyright. All rights reserved.","PeriodicalId":20107,"journal":{"name":"physica status solidi (b)","volume":"54 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85073694","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}
We revisit the problem of the potential, electrical field and charge density in a space charge region. Within the Boltzmann approximation, the asymptotic solution is found analytically. The exact solution everywhere can be found from numerically integrating an analytical function. The solution is compared to the popular abrupt (or depletion) approximation and an analytical approximation is given.This article is protected by copyright. All rights reserved.
{"title":"Space Charge Region Beyond the Abrupt Approximation","authors":"M. Grundmann","doi":"10.1002/pssb.202300257","DOIUrl":"https://doi.org/10.1002/pssb.202300257","url":null,"abstract":"We revisit the problem of the potential, electrical field and charge density in a space charge region. Within the Boltzmann approximation, the asymptotic solution is found analytically. The exact solution everywhere can be found from numerically integrating an analytical function. The solution is compared to the popular abrupt (or depletion) approximation and an analytical approximation is given.This article is protected by copyright. All rights reserved.","PeriodicalId":20107,"journal":{"name":"physica status solidi (b)","volume":"177 3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72868722","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}
Ruirui Bo, Yi Tang, Can Li, Zhengzhong Zhang, Hao Liu
Spin‐dependent electron transport is theoretically studied for a system with an interacting quantum dot sandwiched between a pair of ferromagnetic electrodes. By separately applying an electrical bias or a temperature gradient across the junction, a spin‐polarized current can be obtained and controlled by tuning the gate voltage. Interestingly, regardless of whether the electron transport is driven by the bias voltage or temperature difference, the current in the device always exhibits negative magnetoresistance under the control of the gate voltage. Such magnetoresistance anomalies in the current profile originate from the spin‐selective tunneling channels in quantum dots, which have been proven experimentally feasible. This device scheme is compatible with current technologies and has potential applications in spintronics or spin caloritronics.This article is protected by copyright. All rights reserved.
{"title":"Electrical and Thermal Bias‐Driven Negative Magnetoresistance Effect in an Interacting Quantum Dot","authors":"Ruirui Bo, Yi Tang, Can Li, Zhengzhong Zhang, Hao Liu","doi":"10.1002/pssb.202300266","DOIUrl":"https://doi.org/10.1002/pssb.202300266","url":null,"abstract":"Spin‐dependent electron transport is theoretically studied for a system with an interacting quantum dot sandwiched between a pair of ferromagnetic electrodes. By separately applying an electrical bias or a temperature gradient across the junction, a spin‐polarized current can be obtained and controlled by tuning the gate voltage. Interestingly, regardless of whether the electron transport is driven by the bias voltage or temperature difference, the current in the device always exhibits negative magnetoresistance under the control of the gate voltage. Such magnetoresistance anomalies in the current profile originate from the spin‐selective tunneling channels in quantum dots, which have been proven experimentally feasible. This device scheme is compatible with current technologies and has potential applications in spintronics or spin caloritronics.This article is protected by copyright. All rights reserved.","PeriodicalId":20107,"journal":{"name":"physica status solidi (b)","volume":"94 4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83700357","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}
Andriy Hrytsak, M. Rudko, V. Kapustianyk, Lilya Hrytsak, V. Mykhaylyk
X‐ray luminescence spectra, thermally stimulated luminescence and thermally stimulated conductivity of undoped CsI crystal were investigated in order to reach better understanding of the factors which govern the emission processes in this material. X‐ray luminescence spectra were recorded in the temperature range from 15 to 293 K. The low energy band at 2.2 eV emerging at heating above 120 K has been assigned to the emission of residual impurities. Other two bands peaking at 3.6 and 4.3 eV at 15 K were attributed to the intrinsic emission of CsI due to the self‐trapped excitons. The parameters of the peaks observed in the thermally stimulated luminescence and conductivity of CsI crystal were calculated. Investigations of the thermally stimulated processes in CsI lead to the conclusion that the increase of luminescence of 4.3 eV observed above 70 K is due to release of trapped electrons, which subsequently interact with Vk‐centers and form on‐center STEs. The considerable ionic conductivity observed above 250 K can be explained by influence of the uncontrolled impurities of divalent metal atoms as well as Na+ ions.This article is protected by copyright. All rights reserved.
{"title":"X‐ray luminescence and thermally stimulated processes in CsI crystal","authors":"Andriy Hrytsak, M. Rudko, V. Kapustianyk, Lilya Hrytsak, V. Mykhaylyk","doi":"10.1002/pssb.202300289","DOIUrl":"https://doi.org/10.1002/pssb.202300289","url":null,"abstract":"X‐ray luminescence spectra, thermally stimulated luminescence and thermally stimulated conductivity of undoped CsI crystal were investigated in order to reach better understanding of the factors which govern the emission processes in this material. X‐ray luminescence spectra were recorded in the temperature range from 15 to 293 K. The low energy band at 2.2 eV emerging at heating above 120 K has been assigned to the emission of residual impurities. Other two bands peaking at 3.6 and 4.3 eV at 15 K were attributed to the intrinsic emission of CsI due to the self‐trapped excitons. The parameters of the peaks observed in the thermally stimulated luminescence and conductivity of CsI crystal were calculated. Investigations of the thermally stimulated processes in CsI lead to the conclusion that the increase of luminescence of 4.3 eV observed above 70 K is due to release of trapped electrons, which subsequently interact with Vk‐centers and form on‐center STEs. The considerable ionic conductivity observed above 250 K can be explained by influence of the uncontrolled impurities of divalent metal atoms as well as Na+ ions.This article is protected by copyright. All rights reserved.","PeriodicalId":20107,"journal":{"name":"physica status solidi (b)","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88935075","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}
E. Levchenko, V. Nebol’sin, V. Yuryev, Nada Swayikat
In this paper, we have considered the processes that occur at the interfaces during the nanowires (NWs) growth by the Vapor→Droplet, Liquid→Solid mechanism (VLS), and how that leads to the faceting of the sidewall surface of the NWs. It is shown that faceting is possible only when the Wetting Scenario of the VLS‐growth of the NWs is accomplished due to the exit of the oblique closed packed faces to the sidewall surface of the NWs. Those oblique closed‐packed faces emerge at the crystallization front near the triple phase line. The faceting of the sidewall surface of the NWs can be controlled (i) by changing the contact angle of the catalyst droplet on the top of the NWs with the appropriate catalysts; (ii) by introducing the impurities into the gas phase, which decreases the free surface energy of the catalyst droplet or (iii) by changing the temperature.This article is protected by copyright. All rights reserved.
{"title":"Vapor–Liquid–Solid Growth of Nanowires under the conditions of external faceting","authors":"E. Levchenko, V. Nebol’sin, V. Yuryev, Nada Swayikat","doi":"10.1002/pssb.202300090","DOIUrl":"https://doi.org/10.1002/pssb.202300090","url":null,"abstract":"In this paper, we have considered the processes that occur at the interfaces during the nanowires (NWs) growth by the Vapor→Droplet, Liquid→Solid mechanism (VLS), and how that leads to the faceting of the sidewall surface of the NWs. It is shown that faceting is possible only when the Wetting Scenario of the VLS‐growth of the NWs is accomplished due to the exit of the oblique closed packed faces to the sidewall surface of the NWs. Those oblique closed‐packed faces emerge at the crystallization front near the triple phase line. The faceting of the sidewall surface of the NWs can be controlled (i) by changing the contact angle of the catalyst droplet on the top of the NWs with the appropriate catalysts; (ii) by introducing the impurities into the gas phase, which decreases the free surface energy of the catalyst droplet or (iii) by changing the temperature.This article is protected by copyright. All rights reserved.","PeriodicalId":20107,"journal":{"name":"physica status solidi (b)","volume":"137 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89353875","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}
Stable precipitate takes the essential role for material strengthening in Al‐Mg‐Si alloys. To reveal how the stable precipitate works in material strengthening, a molecular dynamics model is carried out to show the interaction between the edge dislocations and the plate‐shaped β phase of Mg2Si. The critical resolved shear stress (CRSS) is related to the precipitate characteristics including sizes and thickness directions. The CRSS increases with the increase of the precipitate size. When the thickness direction of precipitate changes from [001] to [100], the CRSS increases from 326.76 MPa to 368.7 MPa. This phenomenon is mainly affected by the interaction length between dislocation and β phase. With the increase of interaction length, the interaction time for dislocation to overcome pinning increases. The critical bending angle of dislocation can be affected by the interaction time and shear strain rate. The relationship between the critical bending angle and the CRSS in Al‐Mg‐Si alloy is then established.This article is protected by copyright. All rights reserved.
{"title":"Molecular dynamics simulation of interaction between edge dislocations and stable β phase precipitates in aluminum alloy","authors":"Jian-yu Li, Xuchang Qiu, Shining Kong, Zhao Zhang","doi":"10.1002/pssb.202300246","DOIUrl":"https://doi.org/10.1002/pssb.202300246","url":null,"abstract":"Stable precipitate takes the essential role for material strengthening in Al‐Mg‐Si alloys. To reveal how the stable precipitate works in material strengthening, a molecular dynamics model is carried out to show the interaction between the edge dislocations and the plate‐shaped β phase of Mg2Si. The critical resolved shear stress (CRSS) is related to the precipitate characteristics including sizes and thickness directions. The CRSS increases with the increase of the precipitate size. When the thickness direction of precipitate changes from [001] to [100], the CRSS increases from 326.76 MPa to 368.7 MPa. This phenomenon is mainly affected by the interaction length between dislocation and β phase. With the increase of interaction length, the interaction time for dislocation to overcome pinning increases. The critical bending angle of dislocation can be affected by the interaction time and shear strain rate. The relationship between the critical bending angle and the CRSS in Al‐Mg‐Si alloy is then established.This article is protected by copyright. All rights reserved.","PeriodicalId":20107,"journal":{"name":"physica status solidi (b)","volume":"16 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82376337","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}
Yang Xu, Tao Li, C. Hu, Shenggang Zhou, Yan Wei, Xian Wang, Yong Cao
In this work, the impact of point defects and V doped on the thermodynamic properties of TiB was calculated using the ultra‐soft pseudo‐potential approach of the plane wave based on the density functional theory (DFT). More specifically, based on the Quasi‐harmonic Debye model, the volume, heat capacity, thermal expansion coefficient, and Debye temperature of TiB with B‐vacancy, Ti‐vacancy, V substitutional doped, and V interstitial doped under high temperature and high pressure were systematically analyzed. From the calculated results, it was indicated that the presence of both types of vacancies leads to a decreasing trend for the volume. Particularly, the different forms of V doping could cause lattice distortion and affected supercell volume, whereas their volume was positively correlated with the temperature and negatively correlated with the pressure. The V interstitial doped led to an increased in both the constant volume heat capacity and the constant pressure heat capacity of TiB. In addition, regardless of the vacancy or doping‐based modification of TiB, its constant volume heat capacity increased with the temperature and approached the Dulong‐Petit limit, while the constant pressure heat capacity slowly decreased by increasing the pressure. The presence of vacancies also affected the thermal expansion coefficient of TiB, thereby regulated its high‐temperature ductility. The V interstitial doping approach was beneficial for improving the high‐temperature ductility of TiB, whereas substitutional doping was led to a decreasing trend at high pressure. The Debye temperature of TiB with vacancies was proven more sensitive to pressure changes than the temperature. On the contrary, the V doping had a significant impact on the Debye temperature of TiB, and the Debye temperature of TiB with interstitial V atoms was lower than that of TiB with substitutional V atoms, indicating that the interaction force between the substitutional atoms was higher than that of the interstitial sites.This article is protected by copyright. All rights reserved.
{"title":"Impact of the point defects and V doped on the thermodynamic properties of TiB: first‐principles calculations","authors":"Yang Xu, Tao Li, C. Hu, Shenggang Zhou, Yan Wei, Xian Wang, Yong Cao","doi":"10.1002/pssb.202300214","DOIUrl":"https://doi.org/10.1002/pssb.202300214","url":null,"abstract":"In this work, the impact of point defects and V doped on the thermodynamic properties of TiB was calculated using the ultra‐soft pseudo‐potential approach of the plane wave based on the density functional theory (DFT). More specifically, based on the Quasi‐harmonic Debye model, the volume, heat capacity, thermal expansion coefficient, and Debye temperature of TiB with B‐vacancy, Ti‐vacancy, V substitutional doped, and V interstitial doped under high temperature and high pressure were systematically analyzed. From the calculated results, it was indicated that the presence of both types of vacancies leads to a decreasing trend for the volume. Particularly, the different forms of V doping could cause lattice distortion and affected supercell volume, whereas their volume was positively correlated with the temperature and negatively correlated with the pressure. The V interstitial doped led to an increased in both the constant volume heat capacity and the constant pressure heat capacity of TiB. In addition, regardless of the vacancy or doping‐based modification of TiB, its constant volume heat capacity increased with the temperature and approached the Dulong‐Petit limit, while the constant pressure heat capacity slowly decreased by increasing the pressure. The presence of vacancies also affected the thermal expansion coefficient of TiB, thereby regulated its high‐temperature ductility. The V interstitial doping approach was beneficial for improving the high‐temperature ductility of TiB, whereas substitutional doping was led to a decreasing trend at high pressure. The Debye temperature of TiB with vacancies was proven more sensitive to pressure changes than the temperature. On the contrary, the V doping had a significant impact on the Debye temperature of TiB, and the Debye temperature of TiB with interstitial V atoms was lower than that of TiB with substitutional V atoms, indicating that the interaction force between the substitutional atoms was higher than that of the interstitial sites.This article is protected by copyright. All rights reserved.","PeriodicalId":20107,"journal":{"name":"physica status solidi (b)","volume":"30 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77846082","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}
B. Pécz, M. Németh, F. Giannazzo, A. Kakanakova-Georgieva
2D SiN honeycomb monolayer structures predicted theoretically have been the focus of interest in materials science for a long time, most recently for their semiconducting and ferromagnetic properties. Herein, by investigating metal‐organic chemical vapor deposition processes and direct heat treatment of epitaxial graphene in ammonia flow, the possibility of realizing a certain periodic 2D structure via Si─N bonds under epitaxial graphene on SiC (0001) is reported. The result is of interest because it is compatible with semiconductor material deposition technologies and future use in nanoscience and nanotechnology.
{"title":"On the Possibility of Realizing a 2D Structure of Si─N Bonds by Metal‐Organic Chemical Vapor Deposition","authors":"B. Pécz, M. Németh, F. Giannazzo, A. Kakanakova-Georgieva","doi":"10.1002/pssb.202300262","DOIUrl":"https://doi.org/10.1002/pssb.202300262","url":null,"abstract":"2D SiN honeycomb monolayer structures predicted theoretically have been the focus of interest in materials science for a long time, most recently for their semiconducting and ferromagnetic properties. Herein, by investigating metal‐organic chemical vapor deposition processes and direct heat treatment of epitaxial graphene in ammonia flow, the possibility of realizing a certain periodic 2D structure via Si─N bonds under epitaxial graphene on SiC (0001) is reported. The result is of interest because it is compatible with semiconductor material deposition technologies and future use in nanoscience and nanotechnology.","PeriodicalId":20107,"journal":{"name":"physica status solidi (b)","volume":"3 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87925702","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}
Electron mobility parallel to the c‐axis in 4H‐SiC is experimentally determined by Hall effect measurements over wide donor density and temperature ranges (6 × 1014–3 × 1018 cm−3 and 140–600 K), and it is compared with that perpendicular to the c‐axis obtained for the same conditions. Empirical equations for the mobility along both directions are determined as functions of donor density and temperature, which contribute to the simulation and designing of SiC devices. The origin of the mobility anisotropy is discussed, focusing on the electron effective mass anisotropy. For a precise analysis, taking into account the effect of electrons at a higher energy region than the conduction band bottom, an average electron effective mass considering the energy distribution is theoretically calculated from the band structure of SiC. As a result, it is clarified that the electron mobility anisotropy including its temperature dependence is explained by the average electron effective mass anisotropy.
{"title":"Experimental and Theoretical Study on Anisotropic Electron Mobility in 4H‐SiC","authors":"R. Ishikawa, Hajime Tanaka, M. Kaneko, T. Kimoto","doi":"10.1002/pssb.202300275","DOIUrl":"https://doi.org/10.1002/pssb.202300275","url":null,"abstract":"Electron mobility parallel to the c‐axis in 4H‐SiC is experimentally determined by Hall effect measurements over wide donor density and temperature ranges (6 × 1014–3 × 1018 cm−3 and 140–600 K), and it is compared with that perpendicular to the c‐axis obtained for the same conditions. Empirical equations for the mobility along both directions are determined as functions of donor density and temperature, which contribute to the simulation and designing of SiC devices. The origin of the mobility anisotropy is discussed, focusing on the electron effective mass anisotropy. For a precise analysis, taking into account the effect of electrons at a higher energy region than the conduction band bottom, an average electron effective mass considering the energy distribution is theoretically calculated from the band structure of SiC. As a result, it is clarified that the electron mobility anisotropy including its temperature dependence is explained by the average electron effective mass anisotropy.","PeriodicalId":20107,"journal":{"name":"physica status solidi (b)","volume":"583 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-08-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77216017","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}
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