Carbon electrode‐based perovskite solar cells (C‐PSCs) without a hole transport material (HTM) are cost‐effective and exhibit impressive long‐term stability. The electron transporting layer (ETL) plays a crucial role in planar CsFA‐based HTM‐free C‐PSCs, serving as both an electron transporter and a hole barrier. Herein, the role of low‐TiO2 morphology and thickness on the performance of CsFA‐based HTM‐free C‐PSCs are addressed. Herein, the devices are fabricated with a simple structure fluorine‐doped tin oxide /TiO2 nanoparticles (TiO2 NPs)/Cs0.17FA0.83Pb(I0.83Br0.17)3/carbon, using low‐temperature processes (≤150 °C) under ambient air conditions. By optimizing TiO2 NP layer thickness via spin‐coating speed adjustments, the ETL's coverage and compactness are improved, enhancing the perovskite film's quality, crystallinity, and grain size. An optimal TiO2 ETL at 1500 rpm yields 10.80% efficiency and demonstrates exceptional stability, maintaining 80% efficiency over 120 days in an air environment without encapsulation. The enhancement in device performance is attributed to improved surface properties of the TiO2 NPs ETL, effectively reducing interfacial charge recombination. This straightforwardly supports the development of sustainable, commercial‐ready CsFA HTM‐free C‐PSCs.
{"title":"Low‐Temperature TiO2 Electron Transporting Layer for Planar Hole Transport Material‐Free Carbon Electrode‐CsFA‐Based Perovskite Solar Cells","authors":"Woraprom Passatorntaschakorn, Warunee Khampa, Wongsathon Musikpan, Athipong Ngamjarurojana, Atcharawon Gardchareon, Pipat Ruankham, Chawalit Bhoomanee, Duangmanee Wongratanaphisan","doi":"10.1002/pssa.202400470","DOIUrl":"https://doi.org/10.1002/pssa.202400470","url":null,"abstract":"Carbon electrode‐based perovskite solar cells (C‐PSCs) without a hole transport material (HTM) are cost‐effective and exhibit impressive long‐term stability. The electron transporting layer (ETL) plays a crucial role in planar CsFA‐based HTM‐free C‐PSCs, serving as both an electron transporter and a hole barrier. Herein, the role of low‐TiO<jats:sub>2</jats:sub> morphology and thickness on the performance of CsFA‐based HTM‐free C‐PSCs are addressed. Herein, the devices are fabricated with a simple structure fluorine‐doped tin oxide /TiO<jats:sub>2</jats:sub> nanoparticles (TiO<jats:sub>2</jats:sub> NPs)/Cs<jats:sub>0.17</jats:sub>FA<jats:sub>0.83</jats:sub>Pb(I<jats:sub>0.83</jats:sub>Br<jats:sub>0.17</jats:sub>)<jats:sub>3</jats:sub>/carbon, using low‐temperature processes (≤150 °C) under ambient air conditions. By optimizing TiO<jats:sub>2</jats:sub> NP layer thickness via spin‐coating speed adjustments, the ETL's coverage and compactness are improved, enhancing the perovskite film's quality, crystallinity, and grain size. An optimal TiO<jats:sub>2</jats:sub> ETL at 1500 rpm yields 10.80% efficiency and demonstrates exceptional stability, maintaining 80% efficiency over 120 days in an air environment without encapsulation. The enhancement in device performance is attributed to improved surface properties of the TiO<jats:sub>2</jats:sub> NPs ETL, effectively reducing interfacial charge recombination. This straightforwardly supports the development of sustainable, commercial‐ready CsFA HTM‐free C‐PSCs.","PeriodicalId":20074,"journal":{"name":"Physica Status Solidi A-applications and Materials Science","volume":"18 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141575341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The transient heat conduction equation for the 2D electron gas layer in GaN high‐electron‐mobility transistors is developed. The Schottky barrier height and the conduction band offset seen by electrons in the 2D electron gas layer will be reduced due to self‐heating in the 2D electron gas of GaN high‐electron‐mobility transistors via quantum coupling. Such a reduction will lead to a shift in the threshold voltage. To address this issue, an analytical physical model of self‐heating in the 2D electron gas of a GaN high‐electron‐mobility transistor via quantum coupling impacts on its threshold voltage instability is proposed. The proposed model forecasts that the threshold voltage can have an exponentially dependent relation with the reciprocal of the recovery time after the stress voltage is released, as well as dependencies on the square of the drift velocity, the gate voltage, and the surrounding temperature. The experimentally observed threshold voltage shifts of GaN high‐electron‐mobility transistors confirm such dependent relationships predicted by the proposed physical model. This article provides evidence that the combination of self‐heating in the 2D electron gas layer and quantum coupling may be a possible physical origin of the threshold voltage instability in GaN high‐electron‐mobility transistors.
建立了氮化镓高电子迁移率晶体管中二维电子气层的瞬态热传导方程。由于 GaN 高电子迁移率晶体管中的二维电子气通过量子耦合产生自热，二维电子气层中电子看到的肖特基势垒高度和导带偏移会降低。这种降低将导致阈值电压的移动。为了解决这个问题，我们提出了 GaN 高电子迁移率晶体管二维电子气中通过量子耦合产生的自热对其阈值电压不稳定性影响的分析物理模型。该模型预测阈值电压与应力电压释放后恢复时间的倒数呈指数关系，并与漂移速度的平方、栅极电压和周围温度有关。实验观察到的 GaN 高电子迁移率晶体管的阈值电压偏移证实了所提出的物理模型预测的这种依赖关系。本文提供的证据表明，二维电子气层的自热和量子耦合可能是氮化镓高电子迁移率晶体管阈值电压不稳定性的物理根源。
{"title":"Physical Modeling of Threshold Voltage Instability in GaN High‐Electron‐Mobility Transistors","authors":"Ling‐Feng Mao","doi":"10.1002/pssa.202400479","DOIUrl":"https://doi.org/10.1002/pssa.202400479","url":null,"abstract":"The transient heat conduction equation for the 2D electron gas layer in GaN high‐electron‐mobility transistors is developed. The Schottky barrier height and the conduction band offset seen by electrons in the 2D electron gas layer will be reduced due to self‐heating in the 2D electron gas of GaN high‐electron‐mobility transistors via quantum coupling. Such a reduction will lead to a shift in the threshold voltage. To address this issue, an analytical physical model of self‐heating in the 2D electron gas of a GaN high‐electron‐mobility transistor via quantum coupling impacts on its threshold voltage instability is proposed. The proposed model forecasts that the threshold voltage can have an exponentially dependent relation with the reciprocal of the recovery time after the stress voltage is released, as well as dependencies on the square of the drift velocity, the gate voltage, and the surrounding temperature. The experimentally observed threshold voltage shifts of GaN high‐electron‐mobility transistors confirm such dependent relationships predicted by the proposed physical model. This article provides evidence that the combination of self‐heating in the 2D electron gas layer and quantum coupling may be a possible physical origin of the threshold voltage instability in GaN high‐electron‐mobility transistors.","PeriodicalId":20074,"journal":{"name":"Physica Status Solidi A-applications and Materials Science","volume":"46 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141550986","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Seetepalli Vijaya Krishna, Luka Pavić, Arijeta Bafti, Jana Pisk, Dhanisetti Bhadrarao, Yeti Dana Rao, Ayyagari Venkata Sekhar, Vandana Chitti Babu, Vandana Ravi Kumar, Nalluri Veeraiah
In this investigation, results of dielectric features of Li2O–Al2O3–SiO2 (LAS) glass doped with 3.0 mol% of Cr2O3, MoO3, and WO3 are presented. The investigation spans broad regions of frequency (ω) 10−2–106 Hz and temperature (T) 20–240 °C. Initial characterization of the samples by means of optical absorption spectra reveals that Cr ions do persist in Cr3+oxidation state, whereas fractions of Mo and W ions do present in Mo5+ and W5+ states in addition to predominant presence Mo6+ and W6 + ions, respectively. Infrared spectra suggest that Mo5+ and W5+ ions involve in modifying the network of the glass and induced structural disorder. Dielectric parameters and also σac are observed to be the largest for 40Li2O–5Al2O3–52SiO2:3.0 MoO3 (LASMo) glass followed by 40Li2O–5Al2O3–52SiO2:3.0 WO3 (LASW) and 40Li2O–5Al2O3–52SiO2:3.0 Cr2O3 (LASCr) glasses. Analysis of dipolar relaxation phenomena are carried out using Cole–Cole plots. Analysis of the results of σac suggests that polaronic conduction due to electron transfer between Mo5+ ↔ Mo6+ and W5+ ↔ W6+ is prevailed in case of LASMo and LASW glasses and these glasses are predicted to be useful as cathodes, whereas in LASCr glass, ionic conductivity is dominant and is suitable for electrolytes in ionic batteries.
{"title":"Impact of Cr3+/Mo6+/W6+ Doping on Dipolar Relaxation and AC Conductivity in Li2O–Al2O3–SiO2 Glasses","authors":"Seetepalli Vijaya Krishna, Luka Pavić, Arijeta Bafti, Jana Pisk, Dhanisetti Bhadrarao, Yeti Dana Rao, Ayyagari Venkata Sekhar, Vandana Chitti Babu, Vandana Ravi Kumar, Nalluri Veeraiah","doi":"10.1002/pssa.202400243","DOIUrl":"https://doi.org/10.1002/pssa.202400243","url":null,"abstract":"In this investigation, results of dielectric features of Li<jats:sub>2</jats:sub>O–Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>–SiO<jats:sub>2</jats:sub> (LAS) glass doped with 3.0 mol% of Cr<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>, MoO<jats:sub>3</jats:sub>, and WO<jats:sub>3</jats:sub> are presented. The investigation spans broad regions of frequency (<jats:italic>ω</jats:italic>) 10<jats:sup>−2</jats:sup>–10<jats:sup>6</jats:sup> Hz and temperature (<jats:italic>T</jats:italic>) 20–240 °C. Initial characterization of the samples by means of optical absorption spectra reveals that Cr ions do persist in Cr<jats:sup>3+</jats:sup>oxidation state, whereas fractions of Mo and W ions do present in Mo<jats:sup>5+</jats:sup> and W<jats:sup>5+</jats:sup> states in addition to predominant presence Mo<jats:sup>6+</jats:sup> and W<jats:sup>6 +</jats:sup> ions, respectively. Infrared spectra suggest that Mo<jats:sup>5+</jats:sup> and W<jats:sup>5+</jats:sup> ions involve in modifying the network of the glass and induced structural disorder. Dielectric parameters and also <jats:italic>σ</jats:italic><jats:sub>ac</jats:sub> are observed to be the largest for 40Li<jats:sub>2</jats:sub>O–5Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>–52SiO<jats:sub>2</jats:sub>:3.0 MoO<jats:sub>3</jats:sub> (LASMo) glass followed by 40Li<jats:sub>2</jats:sub>O–5Al<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub>–52SiO<jats:sub>2</jats:sub>:3.0 WO<jats:sub>3</jats:sub> (LASW) and 40Li<jats:sub>2</jats:sub>O–5Al<jats:sub>2</jats:sub>O<jats:sub>3–</jats:sub>52SiO<jats:sub>2</jats:sub>:3.0 Cr<jats:sub>2</jats:sub>O<jats:sub>3</jats:sub> (LASCr) glasses. Analysis of dipolar relaxation phenomena are carried out using Cole–Cole plots. Analysis of the results of <jats:italic>σ</jats:italic><jats:sub>ac</jats:sub> suggests that polaronic conduction due to electron transfer between Mo<jats:sup>5+</jats:sup> ↔ Mo<jats:sup>6+</jats:sup> and W<jats:sup>5+</jats:sup> ↔ W<jats:sup>6+</jats:sup> is prevailed in case of LASMo and LASW glasses and these glasses are predicted to be useful as cathodes, whereas in LASCr glass, ionic conductivity is dominant and is suitable for electrolytes in ionic batteries.","PeriodicalId":20074,"journal":{"name":"Physica Status Solidi A-applications and Materials Science","volume":"39 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141550985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Xiaoli Ji, Ruochen Qiao, Zhihao Xu, Jian Liu, Haoze Yuan
Herein, multiwalled carbon nanotube (MWCNT)/silicon nitride (Si3N4)/polyaniline (PANI) ternary composites are prepared. The preparation method involves attaching carboxyl groups to acid‐modified MWCNT surfaces and amino groups to Si3N4 surfaces modified using a silane‐coupling agent. Then they are combined to binary composites using the solvent‐thermal method. Finally, the ternary composites are prepared by coating PANI on the surface of MWCNT/Si3N4 composites in situ polymerization. The morphology and structure of these composites are characterized through X‐ray diffraction, Fourier‐transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and X‐ray photoelectron spectroscopy. Results show that the reflection loss at 8.8 GHz reaches −42.57 dB when the feeding ratio of MWCNT:Si3N4:PANI is 3:20:40 and the corresponding effective absorption bandwidth reaches 4.06 GHz when the thickness is 3.5 mm. A conductive network with effective electron leaps is formed among MWCNT, Si3N4, and PANI, which increases the conductive loss of the composites. An abundant number of interfaces have formed in the composite materials and promoted dielectric loss. Multiple loss mechanisms and good impedance matching performance endow MWCNT/Si3N4/PANI with excellent microwave absorption performance, and the incorporation of Si3N4 enables the composites to exhibit satisfactory high‐temperature resistance. Thus, these performances render the composites promising materials to address increasing electromagnetic pollution, particularly at high temperatures.
本文制备了多壁碳纳米管（MWCNT）/氮化硅（Si3N4）/聚苯胺（PANI）三元复合材料。制备方法包括在酸修饰的 MWCNT 表面上连接羧基，在使用硅烷偶联剂修饰的 Si3N4 表面上连接氨基。然后使用溶剂热法将它们结合成二元复合材料。最后，通过原位聚合法在 MWCNT/Si3N4 复合材料表面涂覆 PANI，制备出三元复合材料。通过 X 射线衍射、傅立叶变换红外光谱、扫描电子显微镜、透射电子显微镜和 X 射线光电子能谱对这些复合材料的形貌和结构进行了表征。结果表明，当 MWCNT:Si3N4:PANI 的馈入比为 3:20:40 时，8.8 GHz 的反射损耗达到 -42.57 dB；当厚度为 3.5 mm 时，相应的有效吸收带宽达到 4.06 GHz。在 MWCNT、Si3N4 和 PANI 之间形成了具有有效电子跃迁的导电网络，从而增加了复合材料的导电损耗。复合材料中形成了大量的界面，增加了介电损耗。多种损耗机制和良好的阻抗匹配性能使 MWCNT/Si3N4/PANI 具有优异的微波吸收性能，而 Si3N4 的加入则使复合材料表现出令人满意的耐高温性能。因此，这些性能使复合材料成为解决日益严重的电磁污染（尤其是高温电磁污染）的理想材料。
{"title":"Preparation of Multiwalled Carbon Nanotube/Si3N4/Polyaniline Ternary Composites and Their Microwave Absorption Properties","authors":"Xiaoli Ji, Ruochen Qiao, Zhihao Xu, Jian Liu, Haoze Yuan","doi":"10.1002/pssa.202400121","DOIUrl":"https://doi.org/10.1002/pssa.202400121","url":null,"abstract":"Herein, multiwalled carbon nanotube (MWCNT)/silicon nitride (Si<jats:sub>3</jats:sub>N<jats:sub>4</jats:sub>)/polyaniline (PANI) ternary composites are prepared. The preparation method involves attaching carboxyl groups to acid‐modified MWCNT surfaces and amino groups to Si<jats:sub>3</jats:sub>N<jats:sub>4</jats:sub> surfaces modified using a silane‐coupling agent. Then they are combined to binary composites using the solvent‐thermal method. Finally, the ternary composites are prepared by coating PANI on the surface of MWCNT/Si<jats:sub>3</jats:sub>N<jats:sub>4</jats:sub> composites in situ polymerization. The morphology and structure of these composites are characterized through X‐ray diffraction, Fourier‐transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and X‐ray photoelectron spectroscopy. Results show that the reflection loss at 8.8 GHz reaches −42.57 dB when the feeding ratio of MWCNT:Si<jats:sub>3</jats:sub>N<jats:sub>4</jats:sub>:PANI is 3:20:40 and the corresponding effective absorption bandwidth reaches 4.06 GHz when the thickness is 3.5 mm. A conductive network with effective electron leaps is formed among MWCNT, Si<jats:sub>3</jats:sub>N<jats:sub>4</jats:sub>, and PANI, which increases the conductive loss of the composites. An abundant number of interfaces have formed in the composite materials and promoted dielectric loss. Multiple loss mechanisms and good impedance matching performance endow MWCNT/Si<jats:sub>3</jats:sub>N<jats:sub>4</jats:sub>/PANI with excellent microwave absorption performance, and the incorporation of Si<jats:sub>3</jats:sub>N<jats:sub>4</jats:sub> enables the composites to exhibit satisfactory high‐temperature resistance. Thus, these performances render the composites promising materials to address increasing electromagnetic pollution, particularly at high temperatures.","PeriodicalId":20074,"journal":{"name":"Physica Status Solidi A-applications and Materials Science","volume":"25 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141550988","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jyoti Sahu, Bazila Parvez, Mahalaxmi Patil, Ranie S. J., Arpit Sahu, Subhajit Basak, Bhanu Upadhyay, Swaroop Ganguly, Dipankar Saha
Silicon nitride (SiNx) is used for device passivation and capacitance dielectric in GaN monolithic microwave integrated circuits. However, this is a conflicting requirement as passivation requires SiNx to cause tensile strain, and capacitance dielectric primarily demands a high breakdown voltage and large dielectric constant for SiNx, leading to a damaged AlGaN surface during deposition. Two independent SiNx depositions under two different conditions (silicon‐ and nitrogen‐rich) are usually carried out to meet both requirements. Herein, a solution for a unified deposition through interfacial strain analysis on an AlGaN/GaN heterostructure grown on 6H‐SiC imposed by thin film silicon nitride (SiNx), deposited using inductively coupled plasma chemical vapor deposition system is proposed. The strain analysis is done using Raman spectroscopy. The surface morphology of the SiNx is studied using atomic force microscopy. The breakdown characteristics are ascertained from measurements on high electron mobility transistors and metal–insulator–metal capacitors.
{"title":"Strain‐Engineered Unified SiNx Deposition for Device Passivation and Capacitance Dielectric in GaN Monolithic Microwave Integrated Circuit","authors":"Jyoti Sahu, Bazila Parvez, Mahalaxmi Patil, Ranie S. J., Arpit Sahu, Subhajit Basak, Bhanu Upadhyay, Swaroop Ganguly, Dipankar Saha","doi":"10.1002/pssa.202400068","DOIUrl":"https://doi.org/10.1002/pssa.202400068","url":null,"abstract":"Silicon nitride (SiN<jats:sub><jats:italic>x</jats:italic></jats:sub>) is used for device passivation and capacitance dielectric in GaN monolithic microwave integrated circuits. However, this is a conflicting requirement as passivation requires SiN<jats:sub><jats:italic>x</jats:italic></jats:sub> to cause tensile strain, and capacitance dielectric primarily demands a high breakdown voltage and large dielectric constant for SiN<jats:sub><jats:italic>x</jats:italic></jats:sub>, leading to a damaged AlGaN surface during deposition. Two independent SiN<jats:sub><jats:italic>x</jats:italic></jats:sub> depositions under two different conditions (silicon‐ and nitrogen‐rich) are usually carried out to meet both requirements. Herein, a solution for a unified deposition through interfacial strain analysis on an AlGaN/GaN heterostructure grown on 6H‐SiC imposed by thin film silicon nitride (SiN<jats:sub><jats:italic>x</jats:italic></jats:sub>), deposited using inductively coupled plasma chemical vapor deposition system is proposed. The strain analysis is done using Raman spectroscopy. The surface morphology of the SiN<jats:sub><jats:italic>x</jats:italic></jats:sub> is studied using atomic force microscopy. The breakdown characteristics are ascertained from measurements on high electron mobility transistors and metal–insulator–metal capacitors.","PeriodicalId":20074,"journal":{"name":"Physica Status Solidi A-applications and Materials Science","volume":"22 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-07-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141550987","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mirjam Henn, Johannes Ziegler, Christian Huber, Humberto Rodriguez‐Alvarez, Nando Kaminski
Herein, ex situ wet cleaning and in situ high‐temperature annealing of GaN surfaces prior to low pressure chemical vapor deposition (LPCVD) of the SiO2 gate oxide, aiming at effective SiO2‐GaN interface engineering for channel improvement of metal–oxide semiconductor (MOS) transistors, are investigated. Additionally, the combination of in situ annealing and gate oxide deposition in an LPCVD tool provides the advantage of an industrially preferred batch process. A strong impact of the pretreatments on the interface state density and flatband voltage of the fabricated n‐type GaN MOS capacitors is demonstrated. Combined HF wet cleaning and NH annealing result in a low peak interface state density and a close to ideal C–V curve with a nearly ideal flatband voltage . Furthermore, the I–V characteristics exhibit a positive voltage shift of the current onset and substantially reduced I‐V hysteresis, i.e., negligible temporary charging. Physical root causes are assumed to be reduced contamination due to nondestructive yet efficient HF cleaning combined with subsequent high temperatures and the reduction of near‐interface, quasi‐permanent traps due to the saturation of dangling bonds by the annealing in hydrogen‐containing atmosphere.
本文研究了在低压化学气相沉积（LPCVD）二氧化硅栅极氧化物之前对氮化镓表面进行原位湿法清洗和原位高温退火的方法，旨在有效地进行二氧化硅-氮化镓界面工程，以改善金属氧化物半导体（MOS）晶体管的沟道。此外，在 LPCVD 工具中将原位退火和栅极氧化物沉积结合在一起，提供了工业首选批量工艺的优势。结果表明，预处理对所制造的 n 型 GaN MOS 电容器的界面态密度和平带电压有很大影响。结合高频湿法清洗和 NH 退火，可获得较低的峰值界面态密度和接近理想的 C-V 曲线，以及近乎理想的平带电压。此外，I-V 特性显示出电流起始点的正电压偏移，I-V 滞后大大减少，即临时充电可忽略不计。其物理根本原因被认为是无损但高效的高频清洗结合随后的高温减少了污染，以及在含氢气氛中退火使悬空键饱和而减少了近表面准永久陷阱。
{"title":"SiO2‐GaN Interface Improvement by Wet Cleaning and In Situ Annealing for GaN MOS Transistors","authors":"Mirjam Henn, Johannes Ziegler, Christian Huber, Humberto Rodriguez‐Alvarez, Nando Kaminski","doi":"10.1002/pssa.202400065","DOIUrl":"https://doi.org/10.1002/pssa.202400065","url":null,"abstract":"Herein, ex situ wet cleaning and in situ high‐temperature annealing of GaN surfaces prior to low pressure chemical vapor deposition (LPCVD) of the SiO<jats:sub>2</jats:sub> gate oxide, aiming at effective SiO<jats:sub>2</jats:sub>‐GaN interface engineering for channel improvement of metal–oxide semiconductor (MOS) transistors, are investigated. Additionally, the combination of in situ annealing and gate oxide deposition in an LPCVD tool provides the advantage of an industrially preferred batch process. A strong impact of the pretreatments on the interface state density and flatband voltage of the fabricated n‐type GaN MOS capacitors is demonstrated. Combined HF wet cleaning and NH annealing result in a low peak interface state density and a close to ideal <jats:italic>C–V</jats:italic> curve with a nearly ideal flatband voltage . Furthermore, the <jats:italic>I–V</jats:italic> characteristics exhibit a positive voltage shift of the current onset and substantially reduced <jats:italic>I‐V</jats:italic> hysteresis, i.e., negligible temporary charging. Physical root causes are assumed to be reduced contamination due to nondestructive yet efficient HF cleaning combined with subsequent high temperatures and the reduction of near‐interface, quasi‐permanent traps due to the saturation of dangling bonds by the annealing in hydrogen‐containing atmosphere.","PeriodicalId":20074,"journal":{"name":"Physica Status Solidi A-applications and Materials Science","volume":"16 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141518392","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Kinetics of degradation of the nonequilibrium charge carrier lifetime (τ) in Czochralski‐grown (Cz) n‐Si irradiated with 1 MeV electrons at different temperatures in the range from 20 to 285 °C are experimentally and theoretically investigated. It is established that changes in τ are qualitatively and quantitatively determined by the temperature of electron irradiation. Analysis of experimental data using the Shockley‐Read‐Hall (SRH) theory shows that the formation of recombinationally active divacancy‐oxygen (V2O) and vacancy‐oxygen (VO) complexes is the main mechanism of τ degradation in this experiment.
{"title":"Kinetics of Carrier Lifetime Degradation in High‐Temperature 1 MeV Electron‐Irradiated Cz n‐Si Associated with the Formation of Divacancy‐Oxygen Defects","authors":"Mykola Kras'ko, Andrii Kolosiuk, Vasyl Povarchuk, Vasyl Voitovych","doi":"10.1002/pssa.202400300","DOIUrl":"https://doi.org/10.1002/pssa.202400300","url":null,"abstract":"Kinetics of degradation of the nonequilibrium charge carrier lifetime (<jats:italic>τ</jats:italic>) in Czochralski‐grown (Cz) n‐Si irradiated with 1 MeV electrons at different temperatures in the range from 20 to 285 °C are experimentally and theoretically investigated. It is established that changes in <jats:italic>τ</jats:italic> are qualitatively and quantitatively determined by the temperature of electron irradiation. Analysis of experimental data using the Shockley‐Read‐Hall (SRH) theory shows that the formation of recombinationally active divacancy‐oxygen (V<jats:sub>2</jats:sub>O) and vacancy‐oxygen (VO) complexes is the main mechanism of <jats:italic>τ</jats:italic> degradation in this experiment.","PeriodicalId":20074,"journal":{"name":"Physica Status Solidi A-applications and Materials Science","volume":"39 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141518393","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Katja Mustonen, Jukka‐Pekka Lähteenmäki, Hele Savin
Photoluminescence imaging (PLI) is a widely accepted, fast, and contactless method for detecting crystal defects in crystalline silicon solar cells and solar‐grade silicon wafers. However, it is less known by semiconductor wafer manufacturers despite the similarities between photovoltaic (PV) and semiconductor wafers. This study focuses on the detection of microcracks by PLI during high‐quality Czochralski silicon (Cz‐Si) wafer manufacturing. The results show that in case of low resistivity (<25 mΩ cm) wafers, microcracks can be detected at any stage of the processing—even after diamond‐wire slicing. When resistivity increases, visibility of microcracks reduces in process steps that produce uneven surfaces. Nevertheless, they can still be detected after slurry‐wire slicing, lapping, alkaline etching, and polishing. According to the results, unlike resistivity, other material parameters such as dopant species, crystal orientation, and wafer thickness have no similar impact on visibility of microcracks in PLI. Furthermore, all wafers produce a decent photoluminescence (PL) signal without a need for separate sample preparation. Based on these results, general recommendations for the in‐line detection of microcracks for Cz‐Si wafer manufactures are provided. While this study focuses on microcracks, the results and discussion include broader perspectives on the defect characterization in Cz‐Si wafer manufacturing via PLI.
光致发光成像（PLI）是一种广为接受的快速非接触式方法，用于检测晶体硅太阳能电池和太阳能级硅晶片中的晶体缺陷。然而，尽管光伏（PV）硅片和半导体硅片之间存在相似之处，半导体硅片制造商对这种方法却知之甚少。本研究的重点是通过 PLI 检测高质量 Czochralski 硅（Cz-Si）晶片制造过程中的微裂缝。结果表明，对于低电阻率（25 mΩ cm）硅片，在加工的任何阶段--甚至在金刚线切片后--都能检测到微裂纹。当电阻率增加时，在产生不平整表面的加工步骤中，微裂纹的可见度会降低。不过，在浆线切片、研磨、碱性蚀刻和抛光之后，仍然可以检测到微裂纹。研究结果表明，与电阻率不同，其他材料参数（如掺杂剂种类、晶体取向和晶片厚度）对 PLI 中微裂纹的可见性没有类似的影响。此外，所有晶片都能产生良好的光致发光 (PL) 信号，无需单独制备样品。基于这些结果，我们为 Cz-Si 硅片制造商提供了在线检测微裂纹的一般建议。虽然这项研究的重点是微裂纹，但研究结果和讨论从更广泛的角度探讨了通过 PLI 进行 Cz-Si 硅片制造过程中的缺陷表征。
{"title":"Detection of Microcracks in Cz‐Si Wafer Manufacturing by Photoluminescence Imaging","authors":"Katja Mustonen, Jukka‐Pekka Lähteenmäki, Hele Savin","doi":"10.1002/pssa.202400295","DOIUrl":"https://doi.org/10.1002/pssa.202400295","url":null,"abstract":"Photoluminescence imaging (PLI) is a widely accepted, fast, and contactless method for detecting crystal defects in crystalline silicon solar cells and solar‐grade silicon wafers. However, it is less known by semiconductor wafer manufacturers despite the similarities between photovoltaic (PV) and semiconductor wafers. This study focuses on the detection of microcracks by PLI during high‐quality Czochralski silicon (Cz‐Si) wafer manufacturing. The results show that in case of low resistivity (<25 mΩ cm) wafers, microcracks can be detected at any stage of the processing—even after diamond‐wire slicing. When resistivity increases, visibility of microcracks reduces in process steps that produce uneven surfaces. Nevertheless, they can still be detected after slurry‐wire slicing, lapping, alkaline etching, and polishing. According to the results, unlike resistivity, other material parameters such as dopant species, crystal orientation, and wafer thickness have no similar impact on visibility of microcracks in PLI. Furthermore, all wafers produce a decent photoluminescence (PL) signal without a need for separate sample preparation. Based on these results, general recommendations for the in‐line detection of microcracks for Cz‐Si wafer manufactures are provided. While this study focuses on microcracks, the results and discussion include broader perspectives on the defect characterization in Cz‐Si wafer manufacturing via PLI.","PeriodicalId":20074,"journal":{"name":"Physica Status Solidi A-applications and Materials Science","volume":"36 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141518399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Flexible pressure sensors have attracted much attention because of their application prospects in wearable devices, electronic skin, and health monitoring. However, it is still difficult to obtain pressure sensors with excellent performance simply and efficiently. Indium tin oxide (ITO) is a widely used transparent conductive material, and polyvinyl alcohol (PVA) is an elastic insulating material with the advantages of easy processing and stable mechanical properties. ITO nano‐crystalline particles are dispersed into PVA polymers to form an ITO nanocrystalline‐PVA composite film with good electrical conductivity as a piezorestoresistive material, fabricating a pressure sensor with excellent performance. The pressure sensor possesses superior sensitivity (641.15 kPa−1), wide detection range (0–80 kPa), fast response time (10.93 ms), and recovery time (8.05 ms), and excellent stability (more than 1500 cycles). The pressure sensor shows excellent performance in a variety of applications, such as pulse testing, speech recognition, and detection of various joint movements of the human body (such as knees, fingers, elbows, etc.). The sensor has application prospects in health monitoring and motion perception.
柔性压力传感器因其在可穿戴设备、电子皮肤和健康监测方面的应用前景而备受关注。然而，要简单、高效地获得性能优异的压力传感器仍然十分困难。氧化铟锡（ITO）是一种广泛使用的透明导电材料，而聚乙烯醇（PVA）是一种弹性绝缘材料，具有易于加工、机械性能稳定等优点。将 ITO 纳米晶颗粒分散到 PVA 聚合物中，形成具有良好导电性能的 ITO 纳米晶-PVA 复合薄膜，作为压电恢复材料，制作出性能优异的压力传感器。该压力传感器灵敏度高（641.15 kPa-1），检测范围宽（0-80 kPa），响应时间快（10.93 ms），恢复时间短（8.05 ms），稳定性好（超过 1500 次）。该压力传感器在脉搏测试、语音识别和人体各种关节运动（如膝盖、手指、肘部等）的检测等多种应用中表现出卓越的性能。该传感器在健康监测和运动感知方面具有应用前景。
{"title":"Piezoresistive Pressure Sensors with Composite Film of Indium Tin Oxide Nanocrystals Dispersed in Poly(vinyl alcohol)","authors":"Yijie Xia, Pengju Huang, Xinming Lin, Luchao Wu, Ke Li, Chenming Gao, Gaoyu Zhong","doi":"10.1002/pssa.202400334","DOIUrl":"https://doi.org/10.1002/pssa.202400334","url":null,"abstract":"Flexible pressure sensors have attracted much attention because of their application prospects in wearable devices, electronic skin, and health monitoring. However, it is still difficult to obtain pressure sensors with excellent performance simply and efficiently. Indium tin oxide (ITO) is a widely used transparent conductive material, and polyvinyl alcohol (PVA) is an elastic insulating material with the advantages of easy processing and stable mechanical properties. ITO nano‐crystalline particles are dispersed into PVA polymers to form an ITO nanocrystalline‐PVA composite film with good electrical conductivity as a piezorestoresistive material, fabricating a pressure sensor with excellent performance. The pressure sensor possesses superior sensitivity (641.15 kPa<jats:sup>−1</jats:sup>), wide detection range (0–80 kPa), fast response time (10.93 ms), and recovery time (8.05 ms), and excellent stability (more than 1500 cycles). The pressure sensor shows excellent performance in a variety of applications, such as pulse testing, speech recognition, and detection of various joint movements of the human body (such as knees, fingers, elbows, etc.). The sensor has application prospects in health monitoring and motion perception.","PeriodicalId":20074,"journal":{"name":"Physica Status Solidi A-applications and Materials Science","volume":"197 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141518389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mengjie Dai, Wenchao Xing, Yinfeng Zhang, Lun Zhang, Pujun Niu, Ziying Wen, Shengquan Shan, Mei Lyu, Jun Zhu
Tin dioxide (SnO2), one of the best electron transport layer materials for perovskite solar cells (PSCs), has high electrical conductivity and low photocatalytic activity. However, the defects in its inside and surface result in nonradiative recombination at the SnO2/perovskite interface. Complex and time‐consuming passivation methods are not conducive to the commercialization of PSCs, and simple passivation strategies should be used to improve the photovoltaic performance of the devices. Herein, a facile and efficient method is proposed to simultaneously passivate the inside and surface defects by adding histidine (HIS) to SnO2 colloidal solution. This one‐step doping strategy also modulates carrier dynamics at the SnO2/perovskite interface. HIS reduces suspended hydroxyl groups, oxygen vacancies, and uncoordinated Sn4+ defects on the surface of SnO2, as well as uncoordinated Pb2+ and halogen vacancy defects at the buried interface of perovskite. Surprisingly, HIS can prevent perovskite from decomposition to form PbI2, which further decomposes to photoactive metallic Pb0 and I, causing ion migration in PSC. As a result, the PSC efficiency has significantly improved 23.11% after HIS doping. The efficiency of unencapsulated device with HIS is 94% of the primary efficiency after storage in relative humidity = 70 ± 5% for 1000 h.
{"title":"Modified SnO2 Electron Transport Layer by One‐Step Doping with Histidine in Perovskite Solar Cells","authors":"Mengjie Dai, Wenchao Xing, Yinfeng Zhang, Lun Zhang, Pujun Niu, Ziying Wen, Shengquan Shan, Mei Lyu, Jun Zhu","doi":"10.1002/pssa.202400227","DOIUrl":"https://doi.org/10.1002/pssa.202400227","url":null,"abstract":"Tin dioxide (SnO<jats:sub>2</jats:sub>), one of the best electron transport layer materials for perovskite solar cells (PSCs), has high electrical conductivity and low photocatalytic activity. However, the defects in its inside and surface result in nonradiative recombination at the SnO<jats:sub>2</jats:sub>/perovskite interface. Complex and time‐consuming passivation methods are not conducive to the commercialization of PSCs, and simple passivation strategies should be used to improve the photovoltaic performance of the devices. Herein, a facile and efficient method is proposed to simultaneously passivate the inside and surface defects by adding histidine (HIS) to SnO<jats:sub>2</jats:sub> colloidal solution. This one‐step doping strategy also modulates carrier dynamics at the SnO<jats:sub>2</jats:sub>/perovskite interface. HIS reduces suspended hydroxyl groups, oxygen vacancies, and uncoordinated Sn<jats:sup>4+</jats:sup> defects on the surface of SnO<jats:sub>2</jats:sub>, as well as uncoordinated Pb<jats:sup>2+</jats:sup> and halogen vacancy defects at the buried interface of perovskite. Surprisingly, HIS can prevent perovskite from decomposition to form PbI<jats:sub>2</jats:sub>, which further decomposes to photoactive metallic Pb<jats:sup>0</jats:sup> and I, causing ion migration in PSC. As a result, the PSC efficiency has significantly improved 23.11% after HIS doping. The efficiency of unencapsulated device with HIS is 94% of the primary efficiency after storage in relative humidity = 70 ± 5% for 1000 h.","PeriodicalId":20074,"journal":{"name":"Physica Status Solidi A-applications and Materials Science","volume":"151 1","pages":""},"PeriodicalIF":2.0,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141518390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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