Thickness of the resistive switching materials is an essential factor to determine the integration density of resistive switching devices. In this work, we investigated the effect of the thickness of BFO on the WORM resistive switching behavior of Pt/BFO/LNO based devices. The thicknesses of BFO thin films are controlled in the range of 70‐220 nm. All the devices exhibited WORM resistive switching behavior with high ON/OFF ratio (∽10‐2‐10‐4), long term data retention (>3600 s), and reliable endurance (>1000 cycles). The set voltages (Vset) of the devices exhibit an approximately linear relation to the BFO thicknesses, while the highest ON/OFF ratio appears in the device with BFO thickness of 150 nm. The thickness dependent resistive switching characteristic is attributed to the variation of oxygen vacancies and OFF state resistances with the increase of BFO thickness. Our results underline the importance of the thickness of resistive switching materials for the future device applications.This article is protected by copyright. All rights reserved.
{"title":"Effects of BiFeO3 thickness on the write‐once‐read‐many‐times resistive switching behavior of Pt/BiFeO3/LaNiO3 heterostructure","authors":"Yajun Fu, Wei Tang, Jin Wang, Linhong Cao","doi":"10.1002/pssa.202300563","DOIUrl":"https://doi.org/10.1002/pssa.202300563","url":null,"abstract":"Thickness of the resistive switching materials is an essential factor to determine the integration density of resistive switching devices. In this work, we investigated the effect of the thickness of BFO on the WORM resistive switching behavior of Pt/BFO/LNO based devices. The thicknesses of BFO thin films are controlled in the range of 70‐220 nm. All the devices exhibited WORM resistive switching behavior with high ON/OFF ratio (∽10‐2‐10‐4), long term data retention (>3600 s), and reliable endurance (>1000 cycles). The set voltages (Vset) of the devices exhibit an approximately linear relation to the BFO thicknesses, while the highest ON/OFF ratio appears in the device with BFO thickness of 150 nm. The thickness dependent resistive switching characteristic is attributed to the variation of oxygen vacancies and OFF state resistances with the increase of BFO thickness. Our results underline the importance of the thickness of resistive switching materials for the future device applications.This article is protected by copyright. All rights reserved.","PeriodicalId":87717,"journal":{"name":"Physica status solidi (A): Applied research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90895619","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}
Wiktor Luczak, Ciril Reiner-Rozman, M. Muck, Johannes Heitz, G. Mitov, Florian Pfaffeneder, C. von See, A. Hassel, Christoph Kleber
Surface modifications of dental implants play a crucial role for material stability, durability, and patient contentment; hence optimization of the commonly used techniques can have significant impact. Surface properties affect the osseointegration of implants; however, the surface for the optimal osseointegration is still being researched. Herein, the surface roughness and topography of dental implant screws after polishing, sandblasting, and laser treatment via tapping‐mode atomic force microscopy are investigated. The measurements are performed at the implants’ shank, crest, and root sites and evaluated for surface roughness, kurtosis, and skew values. Laser‐treated and sandblasted samples have a significantly higher roughness compared to the machined sample. The roughness at the root of the samples is higher in case of the laser‐treated and machined samples, while lower for the sandblasted implant. It is found that laser treatment leads to a roughness lower than that of sandblasted dental screws but significantly higher than that of mechanically polished implants. Differences in the roughness at different topological sites show the need for more precise treatment of implants in order to optimize the roughness.
{"title":"Laser treatment of dental implants towards an optimized osseointegration: evaluation via TM‐AFM and SEM","authors":"Wiktor Luczak, Ciril Reiner-Rozman, M. Muck, Johannes Heitz, G. Mitov, Florian Pfaffeneder, C. von See, A. Hassel, Christoph Kleber","doi":"10.1002/pssa.202200605","DOIUrl":"https://doi.org/10.1002/pssa.202200605","url":null,"abstract":"Surface modifications of dental implants play a crucial role for material stability, durability, and patient contentment; hence optimization of the commonly used techniques can have significant impact. Surface properties affect the osseointegration of implants; however, the surface for the optimal osseointegration is still being researched. Herein, the surface roughness and topography of dental implant screws after polishing, sandblasting, and laser treatment via tapping‐mode atomic force microscopy are investigated. The measurements are performed at the implants’ shank, crest, and root sites and evaluated for surface roughness, kurtosis, and skew values. Laser‐treated and sandblasted samples have a significantly higher roughness compared to the machined sample. The roughness at the root of the samples is higher in case of the laser‐treated and machined samples, while lower for the sandblasted implant. It is found that laser treatment leads to a roughness lower than that of sandblasted dental screws but significantly higher than that of mechanically polished implants. Differences in the roughness at different topological sites show the need for more precise treatment of implants in order to optimize the roughness.","PeriodicalId":87717,"journal":{"name":"Physica status solidi (A): Applied research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79689305","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}
One of the main targets in modern dentistry is the prevention of caries. Not only daily nutrition plays an important role, but also the so called “pellicle” on the outer surfaced of teeth, which is mainly formed by saliva proteins. Moreover, numerous bacteria are part of this pellicle, which might cause caries by acidic metabolites. In the here presented study, a method for electrophoretic deposition (EPD) of hydroxyapatite (HAP) nanoparticles on gold surfaces, suitable for Surface Plasmon Resonance (SPR) measurements has been developed. An “artificial tooth” has been created and loaded by natural saliva in different concentrations (to form a natural pellicle), while the influence of an environment with different pH values has been studied. It could be demonstrated that even slight acid solutions damage the pellicle significantly within seconds, exposing the HAP to acidic degradation, which would lead to caries in the human oral cavities. This model allows to study pellicle formation as well as degradation in real time. As a practical example, the influence of beverages on the pellicle could be demonstrated.This article is protected by copyright. All rights reserved.
{"title":"An analytical tooth model based on SPR chips coated with hydroxyapatite used for investigation of the acquired dental pellicle","authors":"D. Vornicescu, V. Penta, Michael Keusgen","doi":"10.1002/pssa.202300146","DOIUrl":"https://doi.org/10.1002/pssa.202300146","url":null,"abstract":"One of the main targets in modern dentistry is the prevention of caries. Not only daily nutrition plays an important role, but also the so called “pellicle” on the outer surfaced of teeth, which is mainly formed by saliva proteins. Moreover, numerous bacteria are part of this pellicle, which might cause caries by acidic metabolites. In the here presented study, a method for electrophoretic deposition (EPD) of hydroxyapatite (HAP) nanoparticles on gold surfaces, suitable for Surface Plasmon Resonance (SPR) measurements has been developed. An “artificial tooth” has been created and loaded by natural saliva in different concentrations (to form a natural pellicle), while the influence of an environment with different pH values has been studied. It could be demonstrated that even slight acid solutions damage the pellicle significantly within seconds, exposing the HAP to acidic degradation, which would lead to caries in the human oral cavities. This model allows to study pellicle formation as well as degradation in real time. As a practical example, the influence of beverages on the pellicle could be demonstrated.This article is protected by copyright. All rights reserved.","PeriodicalId":87717,"journal":{"name":"Physica status solidi (A): Applied research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81875354","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}
In this work, a facile and inexpensive ZnO thin film‐based Carbon monoxide gas sensor has been fabricated using a solution‐process technique. To vary the thickness of ZnO thin films, the precursor solutions of two different molarities, 3M and 5M have been spin‐coated over glass substrates. The 3M ZnO thin film device has demonstrated more than two times improvement in sensing response as compared to 5M ZnO films, for 50 ppm Carbon monoxide concentration. Additionally, The 3M ZnO film was found to perform better for low Carbon monoxide concentrations, whereas the 5M ZnO film showed a linear response over a wider range of Carbon monoxide concentrations. The gas sensing mechanism and the impact of film thickness on the performance of the device have been thoroughly studied and discussed, which may open the doors for the design and development of facile and high‐sensitivity metal oxide‐based gas sensors.This article is protected by copyright. All rights reserved.
{"title":"Investigation of the Effect of ZnO Film Thickness Over the Gas Sensor Developed for Sensing Carbon Monoxide","authors":"J. Agrawal, Mayoorika Shukla, Vipul Singh","doi":"10.1002/pssa.202300047","DOIUrl":"https://doi.org/10.1002/pssa.202300047","url":null,"abstract":"In this work, a facile and inexpensive ZnO thin film‐based Carbon monoxide gas sensor has been fabricated using a solution‐process technique. To vary the thickness of ZnO thin films, the precursor solutions of two different molarities, 3M and 5M have been spin‐coated over glass substrates. The 3M ZnO thin film device has demonstrated more than two times improvement in sensing response as compared to 5M ZnO films, for 50 ppm Carbon monoxide concentration. Additionally, The 3M ZnO film was found to perform better for low Carbon monoxide concentrations, whereas the 5M ZnO film showed a linear response over a wider range of Carbon monoxide concentrations. The gas sensing mechanism and the impact of film thickness on the performance of the device have been thoroughly studied and discussed, which may open the doors for the design and development of facile and high‐sensitivity metal oxide‐based gas sensors.This article is protected by copyright. All rights reserved.","PeriodicalId":87717,"journal":{"name":"Physica status solidi (A): Applied research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75300212","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}
Chunhui Wang, Guangyu Yang, S. Ouyang, He Qin, Zhiyong Kan, Wanqi Jie
Accurately assessing the hot workability and flow behavior are crucial in the preparation of high‐performance wrought Mg‐RE alloys. The hot deformation behaviors and workability of Mg‐4.83Gd‐2.36Nd‐0.21Zr alloy were examined via Gleeble 3500 thermo‐simulation tests across a range of deformation temperatures from 350 °C to 450 °C and strain rates ranging from 0.001 s‐1 to 1 s‐1. The experimental results revealed that the flow stress of the experimental alloy decreased as the temperature increased and the strain rate decreased. The activation energies for deformation (Q) of the experiment alloy were calculated by the hyperbolic constitutive equation and ranged from 186.78 to 234.97 kJ mol‐1. Strain compensation was incorporated into the constitutive modeling, resulting in the correlation coefficient (R) of 0.9865 and the average absolute relative error (AARE) of 5.4639%. Further, the processing maps were constructed at different strains based on dynamic material models, from which the feasible processing window of the experimental alloy was determined in the areas of deformation temperatures of 425‐450 °C and strain rates of 0.01‐0.1 s‐1.This article is protected by copyright. All rights reserved.
{"title":"Constitutive modeling of hot deformation behaviors and processing maps of Mg‐4.83Gd‐2.36Nd‐0.21Zr alloy","authors":"Chunhui Wang, Guangyu Yang, S. Ouyang, He Qin, Zhiyong Kan, Wanqi Jie","doi":"10.1002/pssa.202300434","DOIUrl":"https://doi.org/10.1002/pssa.202300434","url":null,"abstract":"Accurately assessing the hot workability and flow behavior are crucial in the preparation of high‐performance wrought Mg‐RE alloys. The hot deformation behaviors and workability of Mg‐4.83Gd‐2.36Nd‐0.21Zr alloy were examined via Gleeble 3500 thermo‐simulation tests across a range of deformation temperatures from 350 °C to 450 °C and strain rates ranging from 0.001 s‐1 to 1 s‐1. The experimental results revealed that the flow stress of the experimental alloy decreased as the temperature increased and the strain rate decreased. The activation energies for deformation (Q) of the experiment alloy were calculated by the hyperbolic constitutive equation and ranged from 186.78 to 234.97 kJ mol‐1. Strain compensation was incorporated into the constitutive modeling, resulting in the correlation coefficient (R) of 0.9865 and the average absolute relative error (AARE) of 5.4639%. Further, the processing maps were constructed at different strains based on dynamic material models, from which the feasible processing window of the experimental alloy was determined in the areas of deformation temperatures of 425‐450 °C and strain rates of 0.01‐0.1 s‐1.This article is protected by copyright. All rights reserved.","PeriodicalId":87717,"journal":{"name":"Physica status solidi (A): Applied research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86612840","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}
Robert Heinke, Thomas Arnold, M. Ehrhardt, P. Lorenz, K. Zimmer
The use of beam‐based technologies to process optical elements with nano‐scale precision enables the fabrication of freeform surfaces. Especially, atmospheric pressure plasma jets (APPJ) have desirable properties such as atmospheric pressure machining, dry processing and direct writing capabilities. However, the presence of metal oxides in optical glasses leads to the formation of non‐volatile reaction products during APPJ etching with fluorine‐containing gas mixtures, forming a residual layer that increases surface roughness and alters etching behavior. To prevent the formation of the residual layer the APPJ process is combined with laser‐cleaning. For a possible future in‐situ cleaning of the residual layer during the plasma process, laser parameter ranges need to be found to remove the residual layer without damaging the glass surface. Therefore, planar etchings are performed by APPJ on N‐BK7 and Zerodur and the etched planes are subsequently laser‐irradiated with varying pulse numbers and fluences. The processed samples are then examined by SEM. For both N‐BK7 and Zerodur, a parameter range is identified that results in clean surfaces. The best machining results are achieved with 2 ‐ 16 pulses and laser fluences of 0.6 ‐ 1.2 J cm‐2 for N‐BK7 and 0.56 ‐ 0.7 J cm‐2 for Zerodur.This article is protected by copyright. All rights reserved.
{"title":"Influence of Fluence and Pulse Number on Laser‐Cleaning of Atmospheric Pressure Plasma Jet Etched Optical Glasses","authors":"Robert Heinke, Thomas Arnold, M. Ehrhardt, P. Lorenz, K. Zimmer","doi":"10.1002/pssa.202300485","DOIUrl":"https://doi.org/10.1002/pssa.202300485","url":null,"abstract":"The use of beam‐based technologies to process optical elements with nano‐scale precision enables the fabrication of freeform surfaces. Especially, atmospheric pressure plasma jets (APPJ) have desirable properties such as atmospheric pressure machining, dry processing and direct writing capabilities. However, the presence of metal oxides in optical glasses leads to the formation of non‐volatile reaction products during APPJ etching with fluorine‐containing gas mixtures, forming a residual layer that increases surface roughness and alters etching behavior. To prevent the formation of the residual layer the APPJ process is combined with laser‐cleaning. For a possible future in‐situ cleaning of the residual layer during the plasma process, laser parameter ranges need to be found to remove the residual layer without damaging the glass surface. Therefore, planar etchings are performed by APPJ on N‐BK7 and Zerodur and the etched planes are subsequently laser‐irradiated with varying pulse numbers and fluences. The processed samples are then examined by SEM. For both N‐BK7 and Zerodur, a parameter range is identified that results in clean surfaces. The best machining results are achieved with 2 ‐ 16 pulses and laser fluences of 0.6 ‐ 1.2 J cm‐2 for N‐BK7 and 0.56 ‐ 0.7 J cm‐2 for Zerodur.This article is protected by copyright. All rights reserved.","PeriodicalId":87717,"journal":{"name":"Physica status solidi (A): Applied research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"85857991","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}
Ran Zhang, Gang Zheng, Bin Cheng, Junchun bai, Xianqi Lin, Kai Xiao, Yukun Wang, Qianyu Hou, Wenhong Sun
The research of the high Al(x = 0.75) component has always been the focus of the AlGaN solar‐blind ultraviolet (UV) detector. However, due to the lattice and thermal mismatch between the AlGaN and the underlying substrate under existing mainstream heteroepitaxial growth methods, the large density of defects, e.g., point defects, screw dislocations, and edge dislocations, has hindered the performances of AlGaN‐based solar‐blind UV photodetectors. A short superlattice polarization‐induced P‐type doping growth technique is used to fabricate a high‐performance AlGaN‐based back‐illuminated solar‐blind UV p‐i‐n photodetector (PD) fabricated on sapphire substrates. The back‐illuminated AlGaN UV‐PD shows a high external quantum efficiency of 70.2%. The peak responsivity (R) reaches 123 mA W−1 at −5 V with a wavelength of 217 nm. Meanwhile, the dark current density is 2.21 × 10−8 A cm−2. Additionally, the UV/visible rejection ratio for the detectors exceeds four orders of magnitude, and the detectivity (D*) is calculated to be 6.7 × 1012 cm Hz1/2 W−1. The device performance parameters can be attributed to the quality of the epilayer and heterojunctions. This technology provides new ideas for nitride semiconductor materials, further bringing a breakthrough in a wide‐bandgap electronics device.
高Al(x = 0.75)组分的研究一直是AlGaN太阳盲紫外(UV)探测器的研究重点。然而，在现有的主流异质外延生长方法下，由于AlGaN与衬底之间的晶格和热失配，大密度的缺陷，如点缺陷、螺旋位错和边缘位错，阻碍了AlGaN基太阳盲紫外光电探测器的性能。采用短超晶格极化诱导P型掺杂生长技术，在蓝宝石衬底上制备了高性能AlGaN背光太阳盲UV P - i - n光电探测器(PD)。背光AlGaN UV - PD显示出70.2%的高外量子效率。在−5 V，波长为217 nm时，峰值响应度R达到123 mA W−1。暗电流密度为2.21 × 10−8 A cm−2。此外，探测器的UV/可见光抑制比超过4个数量级，探测率(D*)计算为6.7 × 1012 cm Hz1/2 W−1。器件性能参数可归因于薄膜和异质结的质量。该技术为氮化半导体材料提供了新的思路，进一步带来了宽带隙电子器件的突破。
{"title":"AlGaN‐Based Solar‐Blind Ultraviolet Detector with a Response Wavelength of 217 nm","authors":"Ran Zhang, Gang Zheng, Bin Cheng, Junchun bai, Xianqi Lin, Kai Xiao, Yukun Wang, Qianyu Hou, Wenhong Sun","doi":"10.1002/pssa.202300231","DOIUrl":"https://doi.org/10.1002/pssa.202300231","url":null,"abstract":"The research of the high Al(x = 0.75) component has always been the focus of the AlGaN solar‐blind ultraviolet (UV) detector. However, due to the lattice and thermal mismatch between the AlGaN and the underlying substrate under existing mainstream heteroepitaxial growth methods, the large density of defects, e.g., point defects, screw dislocations, and edge dislocations, has hindered the performances of AlGaN‐based solar‐blind UV photodetectors. A short superlattice polarization‐induced P‐type doping growth technique is used to fabricate a high‐performance AlGaN‐based back‐illuminated solar‐blind UV p‐i‐n photodetector (PD) fabricated on sapphire substrates. The back‐illuminated AlGaN UV‐PD shows a high external quantum efficiency of 70.2%. The peak responsivity (R) reaches 123 mA W−1 at −5 V with a wavelength of 217 nm. Meanwhile, the dark current density is 2.21 × 10−8 A cm−2. Additionally, the UV/visible rejection ratio for the detectors exceeds four orders of magnitude, and the detectivity (D*) is calculated to be 6.7 × 1012 cm Hz1/2 W−1. The device performance parameters can be attributed to the quality of the epilayer and heterojunctions. This technology provides new ideas for nitride semiconductor materials, further bringing a breakthrough in a wide‐bandgap electronics device.","PeriodicalId":87717,"journal":{"name":"Physica status solidi (A): Applied research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78864299","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}
ReS2 nanosheets have recently attracted attention because of their excellent electrocatalytic properties. It has also been reported that the electrocatalytic activity of solid‐solution ReS2−xSex nanosheets is improved by tuning the bandgap structure through a solid solution with Se. However, Se has application limitations in that it is highly toxic. Thus, herein, solid‐solution ReS2−xTex nanosheets are focused. Solid‐solution ReS2−xTex (x = 0, 0.5, and 1.0) bulk is synthesized by solid‐state reactions. The optical bandgaps of ReS2, ReS1.5Te0.5, and ReSTe are measured to be 1.29, 1.07, and 0.99 eV, respectively. Solid‐solution ReS2−xTex (x = 0, 0.5, and 1.0) nanosheets are obtained by the ultrasonic exfoliation and Li‐intercalation exfoliation of the ReS2−xTex bulks. The typical lateral sizes and thicknesses of the ReS2, ReS1.5Te0.5, and ReSTe nanosheets by ultrasonic exfoliation are 200 and 6 nm, 160 and 3 nm, and 600 and 2 nm, respectively. The typical lateral sizes and thicknesses of ReS2, ReS1.5Te0.5, and ReSTe nanosheets using the Li‐intercalation exfoliation method are 150 and 2 nm, 100 and 1 nm, and 100 and 1 nm, respectively. In the nanosheets obtained from both exfoliation methods, the lateral size is not composition‐dependent, and the thickness decreases with increasing x in ReS2−xTex.
{"title":"Synthesis and Characterization of Solid‐Solution ReS2−xTex (0 ≤ x ≤ 1) Nanosheets","authors":"Shutaro Kawawa, Keitaro Tezuka, Yue Jin Shan","doi":"10.1002/pssa.202300337","DOIUrl":"https://doi.org/10.1002/pssa.202300337","url":null,"abstract":"ReS2 nanosheets have recently attracted attention because of their excellent electrocatalytic properties. It has also been reported that the electrocatalytic activity of solid‐solution ReS2−xSex nanosheets is improved by tuning the bandgap structure through a solid solution with Se. However, Se has application limitations in that it is highly toxic. Thus, herein, solid‐solution ReS2−xTex nanosheets are focused. Solid‐solution ReS2−xTex (x = 0, 0.5, and 1.0) bulk is synthesized by solid‐state reactions. The optical bandgaps of ReS2, ReS1.5Te0.5, and ReSTe are measured to be 1.29, 1.07, and 0.99 eV, respectively. Solid‐solution ReS2−xTex (x = 0, 0.5, and 1.0) nanosheets are obtained by the ultrasonic exfoliation and Li‐intercalation exfoliation of the ReS2−xTex bulks. The typical lateral sizes and thicknesses of the ReS2, ReS1.5Te0.5, and ReSTe nanosheets by ultrasonic exfoliation are 200 and 6 nm, 160 and 3 nm, and 600 and 2 nm, respectively. The typical lateral sizes and thicknesses of ReS2, ReS1.5Te0.5, and ReSTe nanosheets using the Li‐intercalation exfoliation method are 150 and 2 nm, 100 and 1 nm, and 100 and 1 nm, respectively. In the nanosheets obtained from both exfoliation methods, the lateral size is not composition‐dependent, and the thickness decreases with increasing x in ReS2−xTex.","PeriodicalId":87717,"journal":{"name":"Physica status solidi (A): Applied research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91276271","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}
I. Mack, Kawa Rosta, U. Quliyeva, J. Ott, T. Pasanen, V. Vähänissi, Zahra Sadat Jahanshah Rad, J. Lehtiö, P. Laukkanen, C. Soldano, H. Savin
Oxide–semiconductor interface quality has often a direct impact on the electrical properties of devices and on their performance. Traditionally, the properties are characterized through metal–oxide–semiconductor (MOS) structures by depositing a metal layer and measuring the capacitance–voltage (C–V) characteristics. However, metal deposition process itself may have an impact on the oxide and the oxide–semiconductor interface. The impact of magnetron sputtering, e‐beam evaporation, and thermal evaporation on an A l 2 O 3 / S i interface is studied, where atomic layer deposited (ALD) A l 2 O 3 is used, by MOS C–V and corona oxide characterization of semiconductors (COCOS) measurements. The latter allows characterization of the interface also in its original state before metallization. The results show that sputtering induces significant damage at the underlying A l 2 O 3 / S i interface as the measured interface defect density D it increases from 10 11 to 10 13 cm−2 eV. Interestingly, sputtering also generates a high density of positive charges Q tot at the interface as the charge changes from − 2 × 10 12 to + 7 × 10 12 cm − 2 . Thermal evaporation is found to be a softer method, with modest impact on D it and Q tot . Finally, Alnealing heals the damage but has also a significant impact on the charge of the film recovering the characteristic negative charge of A l 2 O 3 (∼−4 × 1012 cm − 2 ).
{"title":"Quantifying the Impact of Al Deposition Method on Underlying Al2O3/Si Interface Quality","authors":"I. Mack, Kawa Rosta, U. Quliyeva, J. Ott, T. Pasanen, V. Vähänissi, Zahra Sadat Jahanshah Rad, J. Lehtiö, P. Laukkanen, C. Soldano, H. Savin","doi":"10.1002/pssa.202200653","DOIUrl":"https://doi.org/10.1002/pssa.202200653","url":null,"abstract":"Oxide–semiconductor interface quality has often a direct impact on the electrical properties of devices and on their performance. Traditionally, the properties are characterized through metal–oxide–semiconductor (MOS) structures by depositing a metal layer and measuring the capacitance–voltage (C–V) characteristics. However, metal deposition process itself may have an impact on the oxide and the oxide–semiconductor interface. The impact of magnetron sputtering, e‐beam evaporation, and thermal evaporation on an A l 2 O 3 / S i interface is studied, where atomic layer deposited (ALD) A l 2 O 3 is used, by MOS C–V and corona oxide characterization of semiconductors (COCOS) measurements. The latter allows characterization of the interface also in its original state before metallization. The results show that sputtering induces significant damage at the underlying A l 2 O 3 / S i interface as the measured interface defect density D it increases from 10 11 to 10 13 cm−2 eV. Interestingly, sputtering also generates a high density of positive charges Q tot at the interface as the charge changes from − 2 × 10 12 to + 7 × 10 12 cm − 2 . Thermal evaporation is found to be a softer method, with modest impact on D it and Q tot . Finally, Alnealing heals the damage but has also a significant impact on the charge of the film recovering the characteristic negative charge of A l 2 O 3 (∼−4 × 1012 cm − 2 ).","PeriodicalId":87717,"journal":{"name":"Physica status solidi (A): Applied research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79561681","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}
Rachid Oubaki, Karima Machkih, H. Larhlimi, O. Abegunde, J. Alami, M. Makha
Using a quaternary compound target, Cu(In,Ga)Se2 films were prepared using one‐step, selenization‐free Direct Current Magneton Sputtering (DcMS) and High Power Impulse Magnetron Sputtering (HiPIMS) methods. We investigated how the sputtering power affected the composition, microstructure, morphology, and electrical characteristics of the films. Film crystallinity was found to be affected by the sputtering power utilized. The films deposited at 0.25 kW were amorphous, whereas those formed at 0.5–1 kW displayed a chalcopyrite structure with a (112)–preferred orientation. With increased sputtering power, the films’ crystal quality improved, displaying a homogeneous and compact morphology free of peeling and cracking. Elemental measurement of the CIGS films revealed that, depending on the deposition method, the film composition deviated from that of the target. The electrical properties of the deposited films varied with increasing sputtering power.This article is protected by copyright. All rights reserved.
{"title":"One‐step DcMS and HiPIMS sputtered CIGS films from a quaternary target","authors":"Rachid Oubaki, Karima Machkih, H. Larhlimi, O. Abegunde, J. Alami, M. Makha","doi":"10.1002/pssa.202300178","DOIUrl":"https://doi.org/10.1002/pssa.202300178","url":null,"abstract":"Using a quaternary compound target, Cu(In,Ga)Se2 films were prepared using one‐step, selenization‐free Direct Current Magneton Sputtering (DcMS) and High Power Impulse Magnetron Sputtering (HiPIMS) methods. We investigated how the sputtering power affected the composition, microstructure, morphology, and electrical characteristics of the films. Film crystallinity was found to be affected by the sputtering power utilized. The films deposited at 0.25 kW were amorphous, whereas those formed at 0.5–1 kW displayed a chalcopyrite structure with a (112)–preferred orientation. With increased sputtering power, the films’ crystal quality improved, displaying a homogeneous and compact morphology free of peeling and cracking. Elemental measurement of the CIGS films revealed that, depending on the deposition method, the film composition deviated from that of the target. The electrical properties of the deposited films varied with increasing sputtering power.This article is protected by copyright. All rights reserved.","PeriodicalId":87717,"journal":{"name":"Physica status solidi (A): Applied research","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2023-08-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90959808","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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