Pub Date : 2024-11-22DOI: 10.1016/j.micrna.2024.208028
Ruihao Zhang , Fayu Wan , Ru Xu , Jiarun Xu , Runtao Song , Long Wang , Xing Zhao
In this paper, we apply AlGaN back-barrier with graded Al composition to effectively improve the RF performance of GaN high electron mobility transistor (HEMT). Simulation results demonstrate that compared with GaN HEMT with fixed Al composition AlGaN back-barrier, graded AlGaN back-barrier HEMT has lower gate capacitance and better two-dimensional electron gas (2DEG) confinement. Its cut-off frequency () and maximum oscillation frequency () reach 100 GHz and 179.8 GHz, respectively, an increase of 12.1 GHz and 42.9 GHz. Due to the lower power supply, graded AlGaN back-barrier HEMT also significantly improves the power added efficiency (PAE) compared with HEMT without back-barrier, increasing 20 %. Moreover, it is found that graded AlGaN back-barrier HEMT has better large-signal performance than fixed AlGaN back-barrier HEMT for the better electron confinement.
{"title":"Research on RF performance of GaN HEMT with graded Al composition AlGaN back-barrier","authors":"Ruihao Zhang , Fayu Wan , Ru Xu , Jiarun Xu , Runtao Song , Long Wang , Xing Zhao","doi":"10.1016/j.micrna.2024.208028","DOIUrl":"10.1016/j.micrna.2024.208028","url":null,"abstract":"<div><div>In this paper, we apply AlGaN back-barrier with graded Al composition to effectively improve the RF performance of GaN high electron mobility transistor (HEMT). Simulation results demonstrate that compared with GaN HEMT with fixed Al composition AlGaN back-barrier, graded AlGaN back-barrier HEMT has lower gate capacitance and better two-dimensional electron gas (2DEG) confinement. Its cut-off frequency (<span><math><mrow><msub><mi>f</mi><mi>t</mi></msub></mrow></math></span>) and maximum oscillation frequency (<span><math><mrow><msub><mi>f</mi><mi>max</mi></msub></mrow></math></span>) reach 100 GHz and 179.8 GHz, respectively, an increase of 12.1 GHz and 42.9 GHz. Due to the lower power supply, graded AlGaN back-barrier HEMT also significantly improves the power added efficiency (<em>PAE</em>) compared with HEMT without back-barrier, increasing 20 %. Moreover, it is found that graded AlGaN back-barrier HEMT has better large-signal performance than fixed AlGaN back-barrier HEMT for the better electron confinement.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"197 ","pages":"Article 208028"},"PeriodicalIF":2.7,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701486","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 : 2024-11-15DOI: 10.1016/j.micrna.2024.208026
Fengqiu Jiang, Yuyu Bu
GaN quantum well infrared detectors are affected by the epitaxy process and the polarization electric field within the quantum well, making it difficult to fabricate actual devices and regulate their performance. This study utilized the APSYS software to build a transport model for GaN quantum well infrared detectors. Based on the optimal quantum well structure GaN/Al0.8Ga0.2N with an absorption peak wavelength around 1550 nm, the modulation of barrier width is used to elucidate the control of E1 energy level in the quantum well, as well as the variation patterns of absorption spectra for quantum well intersubband transitions(ISBT) and polarization electric fields. Under the influence of polarization electric fields, the devices exhibit completely opposite changes in current when subjected to positive and negative biases, respectively. By using Gauss transient spectroscopy, the influence of triangular barriers on the photoelectron transport on the E1 energy level was investigated, and it was determined that the optimal barrier width is 3 nm. At this width, the device exhibits the fastest relaxation within the well and transport between wells. By analyzing the AC impedance, the equivalent circuit of the device was obtained and the rationality of the circuit structure was demonstrated.
{"title":"The impact of barrier modulation on carriers transport in GaN quantum well infrared detectors","authors":"Fengqiu Jiang, Yuyu Bu","doi":"10.1016/j.micrna.2024.208026","DOIUrl":"10.1016/j.micrna.2024.208026","url":null,"abstract":"<div><div>GaN quantum well infrared detectors are affected by the epitaxy process and the polarization electric field within the quantum well, making it difficult to fabricate actual devices and regulate their performance. This study utilized the APSYS software to build a transport model for GaN quantum well infrared detectors. Based on the optimal quantum well structure GaN/Al<sub>0.8</sub>Ga<sub>0.2</sub>N with an absorption peak wavelength around 1550 nm, the modulation of barrier width is used to elucidate the control of E1 energy level in the quantum well, as well as the variation patterns of absorption spectra for quantum well intersubband transitions(ISBT) and polarization electric fields. Under the influence of polarization electric fields, the devices exhibit completely opposite changes in current when subjected to positive and negative biases, respectively. By using Gauss transient spectroscopy, the influence of triangular barriers on the photoelectron transport on the E1 energy level was investigated, and it was determined that the optimal barrier width is 3 nm. At this width, the device exhibits the fastest relaxation within the well and transport between wells. By analyzing the AC impedance, the equivalent circuit of the device was obtained and the rationality of the circuit structure was demonstrated.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"197 ","pages":"Article 208026"},"PeriodicalIF":2.7,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701483","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 : 2024-11-15DOI: 10.1016/j.micrna.2024.208025
Jiale Wang , Kelu Wang , Han Liu , Jie Deng , Zhongwen Zhang , Xiaoyun Liu , Gang Yang
Periodically ordered ZnO nanorod arrays were epitaxially grown on GaN(0001) substrates by polystyrene (PS) nanosphere lithography combined with following hydrothermal growth. The periodicity of ZnO nanorod arrays was varied by choosing PS nanospheres of different diameters. Then Au nanoparticles (NPs) were deposited on the ZnO nanorods to form Au–ZnO nanorod arrays samples. The PATP-to-DMAB model reaction was applied to detect the influence of ZnO nanorods periodicity on the surface plasmon resonance (SPR)-mediated photocatalytic performance of Au–ZnO nanorod arrays samples under 633 nm irradiation. The Au–ZnO nanorod array sample of 800 period presented inferior photocatalytic activities relative to those of individual Au NPs. However, the photocatalytic activities on the Au–ZnO nanorod array sample of 500 nm period were superior relative to those of individual Au NPs. The surface plasmon polaritons (SPP) of plasmonic NPs can change the propagation path of incident light to vertical direction after scattering on them. The Au–ZnO nanorod array sample of 500 nm period possessed the distance between neighbor ZnO rods smaller than the wavelength of irradiation light, and thus the scattered light interfered with each other after the incident light was scattered by the Au NPs on the neighbor ZnO rods. Then the electric field (E-field) intensities near Au NPs were elevated due to the interference effect. Since the SPR-mediated photocatalytic activity is proportional to the square value of local E-field intensity (E2), thus the photocatalytic activities on Au NPs were enhanced. This work might provide a new route to elevate SPR-mediated photocatalytic performance based on the deposition of plasmonic metals on periodically ordered arrays.
{"title":"Interference enhanced SPR-mediated visible-light responsive photocatalysis of periodically ordered ZnO nanorod arrays decorated with Au nanoparticles","authors":"Jiale Wang , Kelu Wang , Han Liu , Jie Deng , Zhongwen Zhang , Xiaoyun Liu , Gang Yang","doi":"10.1016/j.micrna.2024.208025","DOIUrl":"10.1016/j.micrna.2024.208025","url":null,"abstract":"<div><div>Periodically ordered ZnO nanorod arrays were epitaxially grown on GaN(0001) substrates by polystyrene (PS) nanosphere lithography combined with following hydrothermal growth. The periodicity of ZnO nanorod arrays was varied by choosing PS nanospheres of different diameters. Then Au nanoparticles (NPs) were deposited on the ZnO nanorods to form Au–ZnO nanorod arrays samples. The PATP-to-DMAB model reaction was applied to detect the influence of ZnO nanorods periodicity on the surface plasmon resonance (SPR)-mediated photocatalytic performance of Au–ZnO nanorod arrays samples under 633 nm irradiation. The Au–ZnO nanorod array sample of 800 period presented inferior photocatalytic activities relative to those of individual Au NPs. However, the photocatalytic activities on the Au–ZnO nanorod array sample of 500 nm period were superior relative to those of individual Au NPs. The surface plasmon polaritons (SPP) of plasmonic NPs can change the propagation path of incident light to vertical direction after scattering on them. The Au–ZnO nanorod array sample of 500 nm period possessed the distance between neighbor ZnO rods smaller than the wavelength of irradiation light, and thus the scattered light interfered with each other after the incident light was scattered by the Au NPs on the neighbor ZnO rods. Then the electric field (E-field) intensities near Au NPs were elevated due to the interference effect. Since the SPR-mediated photocatalytic activity is proportional to the square value of local E-field intensity (E<sup>2</sup>), thus the photocatalytic activities on Au NPs were enhanced. This work might provide a new route to elevate SPR-mediated photocatalytic performance based on the deposition of plasmonic metals on periodically ordered arrays.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"197 ","pages":"Article 208025"},"PeriodicalIF":2.7,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701485","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 : 2024-11-14DOI: 10.1016/j.micrna.2024.208024
Mukaddar Sk
In this article, we embark on an exciting journey to identify the ideal electron transport layers (ETL) and hole transport layers (HTL) that can significantly boost the efficiency of CsPbI2Br-based solar cells. Utilizing first-principles calculations with the modified Becke-Johnson potential (mBJ) and spin-orbit correction, we uncovered the direct band gap property of CsPbI2Br, measuring an impressive 1.81 eV. Coupled with its remarkable absorption coefficient of 105 cm⁻1 and minimal reflectivity throughout the visible spectrum, this material stands out as an emerging absorber layer for photovoltaic cells. Also, using cutting-edge SCAPS-1D simulations, we explore a range of ETL materials, including TiO2, ZnO, CdS, STO, WS2, and Nb2O5, alongside HTL options like NiO, Spiro, SnS, CuI, Cu2O, and CuSbS2. Our findings reveal that Nb2O5 and Cu2O emerge as the most promising candidates for ETL and HTL to enhance the performance of CsPbI2Br absorbers, opening the door to more efficient solar energy solutions. The efficiencies achieved with the ETL and HTL-based solar cells, specifically Au/CsPbI2Br/Nb2O5/FTO and Au/Cu2O/CsPbI2Br/FTO, are impressive, standing at 17.91 % and 18.13 %, respectively. Moreover, various factors such as the thickness of the absorbing layer, HTL, and ETL, along with total defect density (Nt), donor and acceptor defect densities of both the absorber and the transport layers, and the device temperature, significantly influence the performance metrics of the Au/Cu2O/CsPbI2Br/Nb2O5/FTO solar cell. Our findings reveal impressive values: a maximum open-circuit voltage (Voc) of 1.21 V, a short-circuit current (Jsc) of 32.47 mA/cm2, a fill factor of 87.7 %, and an efficiency (η) of 22.31 %. These findings exceed the previously reported values for halide perovskite based solar cells, underscoring the promise of this research in shaping the future of cutting-edge perovskite-based solar cells.
{"title":"Optimization of efficiency of CsPbI2Br by using different electron transport and hole transport layers: A DFT and SCAPS-1D simulation","authors":"Mukaddar Sk","doi":"10.1016/j.micrna.2024.208024","DOIUrl":"10.1016/j.micrna.2024.208024","url":null,"abstract":"<div><div>In this article, we embark on an exciting journey to identify the ideal electron transport layers (ETL) and hole transport layers (HTL) that can significantly boost the efficiency of CsPbI<sub>2</sub>Br-based solar cells. Utilizing first-principles calculations with the modified Becke-Johnson potential (mBJ) and spin-orbit correction, we uncovered the direct band gap property of CsPbI<sub>2</sub>Br, measuring an impressive 1.81 eV. Coupled with its remarkable absorption coefficient of 10<sup>5</sup> cm⁻<sup>1</sup> and minimal reflectivity throughout the visible spectrum, this material stands out as an emerging absorber layer for photovoltaic cells. Also, using cutting-edge SCAPS-1D simulations, we explore a range of ETL materials, including TiO<sub>2</sub>, ZnO, CdS, STO, WS<sub>2</sub>, and Nb<sub>2</sub>O<sub>5</sub>, alongside HTL options like NiO, Spiro, SnS, CuI, Cu<sub>2</sub>O, and CuSbS<sub>2</sub>. Our findings reveal that Nb<sub>2</sub>O<sub>5</sub> and Cu<sub>2</sub>O emerge as the most promising candidates for ETL and HTL to enhance the performance of CsPbI<sub>2</sub>Br absorbers, opening the door to more efficient solar energy solutions. The efficiencies achieved with the ETL and HTL-based solar cells, specifically Au/CsPbI<sub>2</sub>Br/Nb<sub>2</sub>O<sub>5</sub>/FTO and Au/Cu<sub>2</sub>O/CsPbI<sub>2</sub>Br/FTO, are impressive, standing at 17.91 % and 18.13 %, respectively. Moreover, various factors such as the thickness of the absorbing layer, HTL, and ETL, along with total defect density (N<sub>t</sub>), donor and acceptor defect densities of both the absorber and the transport layers, and the device temperature, significantly influence the performance metrics of the Au/Cu<sub>2</sub>O/CsPbI<sub>2</sub>Br/Nb<sub>2</sub>O<sub>5</sub>/FTO solar cell. Our findings reveal impressive values: a maximum open-circuit voltage (V<sub>oc</sub>) of 1.21 V, a short-circuit current (J<sub>sc</sub>) of 32.47 mA/cm<sup>2</sup>, a fill factor of 87.7 %, and an efficiency (η) of 22.31 %. These findings exceed the previously reported values for halide perovskite based solar cells, underscoring the promise of this research in shaping the future of cutting-edge perovskite-based solar cells.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"197 ","pages":"Article 208024"},"PeriodicalIF":2.7,"publicationDate":"2024-11-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656163","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 : 2024-11-13DOI: 10.1016/j.micrna.2024.208021
Shengxu Zhao , Yue Yuan , Yue Feng , Xin Liu , Chi Liu , Shaozhi Pu , Tao Shen
MoS2 has great potential as a humidity sensor, and doping is considered the most promising method to enhance the adsorption of H2O molecule by MoS2. Unfortunately, vacancy doping sacrifices the stability of the material while enhancing adsorption efficiency. Here, we use Fe, Co, Ni, Cu to modify the surface of MoS2 and study the adsorption characteristics of H2O molecule on MoS2 before and after modification. The first principles calculations further indicate that partial transition metal (TM) doping can induce spin polarization in MoS2. Spin polarization further enhances orbital hybridization between atoms, thereby improving adsorption performance. On the basis of qualitative analysis of thermodynamic stability and electrical properties, quantitative analysis was conducted on adsorption energy and charge transfer. The results indicate that the adsorption energy, in descending order, is Fe–MoS2 > Co–MoS2 > Ni–MoS2 > Cu–MoS2 > MoS2. Compared with MoS2, Fe–MoS2 has the best adsorption effect among the four doping systems, with an adsorption energy increase of 22.1 times. Importantly, simulations of desorption time have demonstrated that Fe–MoS2 and Co–MoS2 exhibit a significant reduction in desorption time with increasing temperature and can be rapidly recycled.
{"title":"The effect of MoS2 modified with transition metal (Fe, Co, Ni, Cu) on H2O adsorption: A first principle study","authors":"Shengxu Zhao , Yue Yuan , Yue Feng , Xin Liu , Chi Liu , Shaozhi Pu , Tao Shen","doi":"10.1016/j.micrna.2024.208021","DOIUrl":"10.1016/j.micrna.2024.208021","url":null,"abstract":"<div><div>MoS<sub>2</sub> has great potential as a humidity sensor, and doping is considered the most promising method to enhance the adsorption of H<sub>2</sub>O molecule by MoS<sub>2</sub>. Unfortunately, vacancy doping sacrifices the stability of the material while enhancing adsorption efficiency. Here, we use Fe, Co, Ni, Cu to modify the surface of MoS<sub>2</sub> and study the adsorption characteristics of H<sub>2</sub>O molecule on MoS<sub>2</sub> before and after modification. The first principles calculations further indicate that partial transition metal (TM) doping can induce spin polarization in MoS<sub>2</sub>. Spin polarization further enhances orbital hybridization between atoms, thereby improving adsorption performance. On the basis of qualitative analysis of thermodynamic stability and electrical properties, quantitative analysis was conducted on adsorption energy and charge transfer. The results indicate that the adsorption energy, in descending order, is Fe–MoS<sub>2</sub> > Co–MoS<sub>2</sub> > Ni–MoS<sub>2</sub> > Cu–MoS<sub>2</sub> > MoS<sub>2</sub>. Compared with MoS<sub>2</sub>, Fe–MoS<sub>2</sub> has the best adsorption effect among the four doping systems, with an adsorption energy increase of 22.1 times. Importantly, simulations of desorption time have demonstrated that Fe–MoS<sub>2</sub> and Co–MoS<sub>2</sub> exhibit a significant reduction in desorption time with increasing temperature and can be rapidly recycled.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"197 ","pages":"Article 208021"},"PeriodicalIF":2.7,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142656162","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}
Micro cavity structures are extensively utilized in semiconductor micro- and nanosensor devices, especially spherical microcavity, whose high Q value not only significantly improves the sensitivity of the sensors, but also enhances their reliability in complex environments. The integration of this structure not only optimizes the performance of the sensor, but also provides the possibility for high-precision detection. In this study, a thermoelectric coupling method for controllable migration of microsphere cavity inside silicon materials is proposed in order to achieve stable formation of the internal microsphere cavity structure. The directional migration mechanism of atoms on the surface of microsphere cavities in silicon substrates under an electric field is explored using a phase field model. The model indicates that changes in the total free energy density induce a solid-gas phase transition on the surface of the microsphere cavity. It is shown that the migration velocity of the microsphere cavity increases proportionally with the electric field strength, and the migration distance increases by approximately 9 % for every 10 % increase in electric field strength. The migration direction aligns with the direction of the electric field. Simulation results validate the theoretical accuracy, the feasibility of controllable migration by thermoelectric coupling effect in conductive materials through experimental studies. This study provides novel methods and insights for fabricating high-quality spherical cavity in silicon materials and preparing highly sensitive micro- and nanosensor devices.
{"title":"Research on controllable processing technology of microsphere cavity inside silicon substrates utilizing thermoelectric coupling effect","authors":"Linan Zhang, Haiping Liu, Tongzhou Shen, Liqun Wu, Hongcheng Wang, Hongying Liu","doi":"10.1016/j.micrna.2024.208022","DOIUrl":"10.1016/j.micrna.2024.208022","url":null,"abstract":"<div><div>Micro cavity structures are extensively utilized in semiconductor micro- and nanosensor devices, especially spherical microcavity, whose high Q value not only significantly improves the sensitivity of the sensors, but also enhances their reliability in complex environments. The integration of this structure not only optimizes the performance of the sensor, but also provides the possibility for high-precision detection. In this study, a thermoelectric coupling method for controllable migration of microsphere cavity inside silicon materials is proposed in order to achieve stable formation of the internal microsphere cavity structure. The directional migration mechanism of atoms on the surface of microsphere cavities in silicon substrates under an electric field is explored using a phase field model. The model indicates that changes in the total free energy density induce a solid-gas phase transition on the surface of the microsphere cavity. It is shown that the migration velocity of the microsphere cavity increases proportionally with the electric field strength, and the migration distance increases by approximately 9 % for every 10 % increase in electric field strength. The migration direction aligns with the direction of the electric field. Simulation results validate the theoretical accuracy, the feasibility of controllable migration by thermoelectric coupling effect in conductive materials through experimental studies. This study provides novel methods and insights for fabricating high-quality spherical cavity in silicon materials and preparing highly sensitive micro- and nanosensor devices.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"197 ","pages":"Article 208022"},"PeriodicalIF":2.7,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701482","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 : 2024-11-12DOI: 10.1016/j.micrna.2024.208020
Wenting Yang , Li-Cai Zhao
This study explores the mechanical properties of both single-layered and multi-layered tolanene nanosheets via molecular dynamics (MD) simulations. The effects of critical parameters such as size, temperature, and defects on the mechanical behavior of armchair and zigzag configurations of single-layer Tolanene nanosheets are analyzed. Key mechanical properties, including Young's modulus, ultimate stress, fracture stress, and fracture strain, are evaluated based on the stress-strain curve. It is observed that the zigzag configuration exhibits a higher Young's modulus compared to the armchair configuration. However, the armchair structure shows greater ultimate stress than the zigzag configuration. An increase in temperature or the introduction of vacancy defects leads to a degradation of mechanical properties in both configurations. The sensitivity of Young's modulus to temperature is more pronounced in the zigzag configuration than in the armchair, even though the armchair configuration generally has a higher Young's modulus. Additionally, increasing the number of layers in the nanosheets results in an enhancement of Young's modulus, with the armchair configuration showing more significant improvement than the zigzag configuration. The variation in Young's modulus with increasing layers is minimal for the zigzag configuration.
{"title":"Comprehensive study of Tolanene's mechanical properties: Effects of temperature, layering, orientation, and defects","authors":"Wenting Yang , Li-Cai Zhao","doi":"10.1016/j.micrna.2024.208020","DOIUrl":"10.1016/j.micrna.2024.208020","url":null,"abstract":"<div><div>This study explores the mechanical properties of both single-layered and multi-layered tolanene nanosheets via molecular dynamics (MD) simulations. The effects of critical parameters such as size, temperature, and defects on the mechanical behavior of armchair and zigzag configurations of single-layer Tolanene nanosheets are analyzed. Key mechanical properties, including Young's modulus, ultimate stress, fracture stress, and fracture strain, are evaluated based on the stress-strain curve. It is observed that the zigzag configuration exhibits a higher Young's modulus compared to the armchair configuration. However, the armchair structure shows greater ultimate stress than the zigzag configuration. An increase in temperature or the introduction of vacancy defects leads to a degradation of mechanical properties in both configurations. The sensitivity of Young's modulus to temperature is more pronounced in the zigzag configuration than in the armchair, even though the armchair configuration generally has a higher Young's modulus. Additionally, increasing the number of layers in the nanosheets results in an enhancement of Young's modulus, with the armchair configuration showing more significant improvement than the zigzag configuration. The variation in Young's modulus with increasing layers is minimal for the zigzag configuration.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"197 ","pages":"Article 208020"},"PeriodicalIF":2.7,"publicationDate":"2024-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701484","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 : 2024-11-09DOI: 10.1016/j.micrna.2024.208015
Atabek E. Atamuratov , Bahor O. Jabbarova , Makhkam M. Khalilloev , Dilshod R. Rajapov , Ahmed Yusupov , Jean Chamberlain Chedjou , Gurdial Blugan , Kamoladdin Saidov
In this work the impact of the doping profile in the source and drain areas on the self-heating effect in SOI FinFET is simulated at different doping levels in the channel. Constant profile as well as two types of analytical profiles are considered. The impact of the doping profile on the threshold voltage and on the ratio Ion/Ioff at different doping levels of the channel is also considered. To consider the self-heating effect the thermodynamic transport model in TCAD Sentaurus software is used for simulation. The results of simulation show that self-heating effect, threshold voltage, and Ion/Ioff ratio considerably depend on the doping profile in source and drain areas.
在这项研究中，我们模拟了在沟道中不同掺杂水平下，源极和漏极区域的掺杂曲线对 SOI FinFET 自热效应的影响。考虑了恒定剖面和两种分析剖面。此外，还考虑了在沟道不同掺杂水平下，掺杂曲线对阈值电压和离子/离子关比例的影响。为了考虑自热效应，使用了 TCAD Sentaurus 软件中的热力学传输模型进行模拟。仿真结果表明，自热效应、阈值电压和 Ion/Ioff 比率在很大程度上取决于源极和漏极区域的掺杂情况。
{"title":"Impact of source (drain) doping profiles and channel doping level on self-heating effect in FinFET","authors":"Atabek E. Atamuratov , Bahor O. Jabbarova , Makhkam M. Khalilloev , Dilshod R. Rajapov , Ahmed Yusupov , Jean Chamberlain Chedjou , Gurdial Blugan , Kamoladdin Saidov","doi":"10.1016/j.micrna.2024.208015","DOIUrl":"10.1016/j.micrna.2024.208015","url":null,"abstract":"<div><div>In this work the impact of the doping profile in the source and drain areas on the self-heating effect in SOI FinFET is simulated at different doping levels in the channel. Constant profile as well as two types of analytical profiles are considered. The impact of the doping profile on the threshold voltage and on the ratio I<sub>on</sub>/I<sub>off</sub> at different doping levels of the channel is also considered. To consider the self-heating effect the thermodynamic transport model in TCAD Sentaurus software is used for simulation. The results of simulation show that self-heating effect, threshold voltage, and Ion/Ioff ratio considerably depend on the doping profile in source and drain areas.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"197 ","pages":"Article 208015"},"PeriodicalIF":2.7,"publicationDate":"2024-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142701481","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-11-08DOI: 10.1016/j.micrna.2024.208013
Ankush Chattopadhyay
This paper reports ferroelectric (FE) oxide based graded-channel junctionless FET featuring the negative capacitance effects in nano-scale regime. The linearity nature of its response is analyzed on the basis of third order interception point (), harmonic interception voltages of 2nd and 3rd orders (, ) and intermodulation distortion (). Influence of fundamental device’s parameters such as, gate and underlap length, ferroelectric oxide thickness, graded channel doping and operating temperature on its linear behavior is observed and analyzed in detail. The subthreshold slope is also found to go below 60mV/dec for optimum features, obtaining the NC characteristics. In its circuit application part, a cascode amplifier is designed using the proposed device showing variations due to the change in the proposed device dimensions. The proposed device is designed and simulated using Silvaco ATLAS device simulator, which is calibrated with the available experimental results. Therefore, the present study is quite relevant in recent days for low power analog applications.
{"title":"Linearity analysis of FE-based graded channel junctionless FET obtaining negative capacitance for low power applications","authors":"Ankush Chattopadhyay","doi":"10.1016/j.micrna.2024.208013","DOIUrl":"10.1016/j.micrna.2024.208013","url":null,"abstract":"<div><div>This paper reports ferroelectric (FE) oxide based graded-channel junctionless FET featuring the negative capacitance effects in nano-scale regime. The linearity nature of its response is analyzed on the basis of third order interception point (<span><math><msub><mrow><mi>P</mi></mrow><mrow><mi>I</mi><mi>P</mi><mn>3</mn></mrow></msub></math></span>), harmonic interception voltages of 2nd and 3rd orders (<span><math><mrow><mi>V</mi><mi>I</mi><msub><mrow><mi>P</mi></mrow><mrow><mn>2</mn></mrow></msub></mrow></math></span>, <span><math><mrow><mi>V</mi><mi>I</mi><msub><mrow><mi>P</mi></mrow><mrow><mn>3</mn></mrow></msub></mrow></math></span>) and intermodulation distortion (<span><math><mrow><mi>I</mi><mi>M</mi><msub><mrow><mi>D</mi></mrow><mrow><mn>3</mn></mrow></msub></mrow></math></span>). Influence of fundamental device’s parameters such as, gate and underlap length, ferroelectric oxide thickness, graded channel doping and operating temperature on its linear behavior is observed and analyzed in detail. The subthreshold slope is also found to go below 60mV/dec for optimum features, obtaining the NC characteristics. In its circuit application part, a cascode amplifier is designed using the proposed device showing variations due to the change in the proposed device dimensions. The proposed device is designed and simulated using Silvaco ATLAS device simulator, which is calibrated with the available experimental results. Therefore, the present study is quite relevant in recent days for low power analog applications.</div></div>","PeriodicalId":100923,"journal":{"name":"Micro and Nanostructures","volume":"196 ","pages":"Article 208013"},"PeriodicalIF":2.7,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142653509","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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