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(This page is in Chinese only.  For details, please kindly contact our representative.)   1.　概述 固态电池作为一个全新的技术方案，引起了广泛的研究兴趣，并得到了诸多探索。众所周知，固态电池的电解质和电极材料均是固态的，两者间界面材料相容，才能有效地传导离子，从而降低电池内部阻抗。   化学组成与电子能带结构分析能够帮助了解电解质与电极之间的界面性质，这对于半导体材料、纳米材料以及电池器件的研究十分重要。可利用TOF-SIMS、XPS、AES和UPS/LEIPS等技术来表征固态电池LiPON电解质和LiCoO2正极之间的界面，以获得相应成分、化学态和能带的信息。XPS和TOF-SIMS实验结果表明，在LiPON/LiCoO2 界面附近存在一个具有特定化学态的界面层，在该界面层发现了LiCoO2被还原的现象。为进一步了解界面上所发生的化学反应机制，可以利用UPS（紫外光电子能谱）和LEIPS (低能量反光电子能谱)来分析能带电子结构，为优化电池制备工艺提供指导。   2.　紫外光电子能谱和低能量反光电子能谱 如图1所示，紫外光电子能谱（UPS），基于光电效应，利用紫外光（hν=21.22 eV）激发价带电子, 可以获取样品价带位置（VB/HOMO）、功函数（Ф）和电离势（IE）信息。低能量反光电子能谱（LEIPS）是采用低能量电子（小于5 eV）入射到样品表面，与未占据态（导带）耦合释放出光子，然后通过光子探测器对发射光子进行检测，从而获取样品导带（CB/LUMO）和电子亲和势（EA）的信息。将UPS与LEIPS结合，可以完整地表征出样品的能带电子结构。 图1 UPS和LEIPS的基本原理   PHI XPS系统采用低能量电子（小于5 eV）作为LEIPS入射电子源，可以减弱电子束照射引起的样品损伤，提供更加可靠的导带信息。如图2所示，PHI XPS 系统在分析腔体上集成了XPS、UPS和LEIPS，可以原位对样品完成组分、化学态、价带和导带等完整电子结构的测试，结合Ar离子枪和团簇离子枪（GCIB/C60）可以进一步完成深度方向上电子结构的探测。 图2 PHI XPS系统功能示意图   3.　应用 从固态电池材料中制备了的LiPON和LiCoO2两种薄膜，然后利用UPS和LEIPS（如图2所示）分别对两种薄膜进行测试，全面获取两种材料相对于真空能级的电子能带结构。   图3 LEIPS和UPS测试的示意图   我们知道费米能级表征了电子填充能级的强弱。图4结果显示LiCoO2 的费米能级比LiPON的低，因此当LiPON电解质层沉积到LiCoO2电极界面时，电子倾向于从LiPON扩散到LiCoO2中，从而引起LiCoO2的还原。由此可见，通过UPS和LEIPS获取能带结构，能帮助解释XPS, TOF-SIMS以及AES的实验结果，进一步探究界面化学反应机制。 图4 LiPON和LiCoO2能带结构   4.　结论 PHI XPS 系统采用低能量反光电子能谱（LEIPS），可以避免电子束对样品的辐照损伤。同时，PHI XPS 分析腔体集成的XPS、UPS和LEIPS，可以对样品原位获取完整的电子结构探测。在这项研究中，准确的能级排列图有助于深入理解电解质/电极界面特性。

(This page is in Chinese only.  For details, please kindly contact our representative.)   1.　概述 锂离子电池 (LIB)具有工作电压高、能量密度大、循环寿命长、无记忆效应等优点，被广泛用于智能手机等便携电子设备，同时大容量锂离子电池已经成为电动汽车的主要动力电源。但是，现有的锂电池存在一些安全隐患。近日国家应急管理部公布的新能源汽车火灾数据显示，在2022年的第一季度，电动车发生自燃的事故有640起，平均每日有7例事故。这是因为在传统的锂离子电池中使用的是有机液态电解质，这些有机物分解电压较低、易燃易爆，即使是轻微的损坏也可能导致爆炸或引起火灾。   图1. 电动汽车着火安全问题   全固态电池（ASSBs）是一种使用固体电极和固体电解质的电池，由于采用了固态电解质替代传统的有机液态电解质，有望从根本上解决电池的安全性问题，还能进一步提升锂电池的能量密度和循环寿命，符合未来高安全性高能量密度锂电池发展的方向。然而，固体电解质（SE）和电极界面处的内阻是固态电池实际应用的最大障碍之一，因为该界面处的内阻限制了锂离子在充电/放电循环期间的传输效率。   2.　扫描俄歇电子能谱 扫描俄歇电子能谱（AES）是研究固体电解质材料和界面的显微结构和组分的重要方法，但是AES仪器的入射电子束照射容易引起样品损伤。例如LiPON电解质在电子束的照射下，易产生还原现象。使用AES设备的低电流模式可以减少对样品的损伤，同时性能优异的能量分析器可以提供重要组分Li的化学态信息。   图2 PHI VersaProbe系列XPS设备的扫描俄歇电子能谱配件   3.　应用 本案例样品采用多层结构，如图3样品截面的俄歇电子能谱SEM所示，多层结构分别为LiPON电解质，LiCoO2正极，Pt/Ti集流体和玻璃基底。为准确获取固态电池的化学性质及组成，采用AES低电流模式进行检测。图4结果表明，俄歇谱图中32 eV和40 eV处的信号分别对应LiPON和LiCoO2中的不同Li化学状态。此外，LiPON和LiCoO2的Li化学态分布图与SEM影像一一对应（见图3）。Li KVV俄歇谱证明了使用低电流AES检测，可以避免LiPON电解质的还原，从而得到Li准确化学态的分析结果。   图3 俄歇电子能谱的SEM影像与锂化学状态图的叠加   图4 锂的KVV型俄歇跃迁能谱   4.　结论 PHI VersaProbe系列XPS可搭载高空间分辨率和高灵敏度的扫描俄歇电子能谱配件，通过采用低电流且短时间的电子照射，在确保没有引起样品损伤的情况下，可以快速获得高能量分辨的AES化学状态图像。总而言之，pA-AES能够保证不同材料的真实性并提供可靠的分析结果。  

(This page is in Chinese only.  For details, please kindly contact our representative.)   　　X射线光电子能谱（X-ray Photoelectron Spectroscopy，简称XPS），是一种基于光电效应的电子能谱，是测量电子能量的谱学技术，最初是被用来进行化学分析，因此也被称为化学分析电子能谱 （Electron Spectroscopy for Chemical Analysis，简称ESCA）。   　　表面是指物体最表层的几层原子和覆盖在其上面的一些外来原子和分子所形成的的表面层。表面的厚度一般在零点几纳米到几个纳米之间，表面层具有独特的性质，与内层性质有很大差异甚至完全不同。由于表面在现代科学技术中的作用日益重要，所以科学家们把表面称为物质第四态，叫做“表面态”。表面态指表面的局域电子能级，是一些在与固体体相离域电子能带交换电子或共享电子方面具有活性的能级。 　　XPS是一种重要的常规表面成分分析技术，其分析深度约为0~100埃，也就是10nm以内（目前ULVAC-PHI的HAXPES具有双阳极靶、双单色器，已经具备30nm深度的无损分析能力）。它不但可以提供分子结构和原子价态方面的信息，还能提供各种化合物的元素组成和含量、化学状态、分子结构、化学键方面的信息，可以给出表面、微小区域和深度分布等方面的信息。XPS可用于定性和半定量分析除H、He以外所有表面元素，因而广泛地应用于材料研究的各个领域。   Resource from XPS International – XPS Periodic Table   发展简史 　　1887年，海因里希·鲁道夫·赫兹发现了光电效应；1895年伦琴发现X射线；1905年，爱因斯坦解释了该现象（并为此获得了1921年的诺贝尔物理学奖）。两年后的1907年，P.D. Innes用伦琴管、亥姆霍兹线圈、磁场半球（电子能量分析仪）和照像平版做实验来记录宽带发射电子和速度的函数关系，他的实验事实上记录了人类第一条X射线光电子能谱。其他研究者如亨利·莫塞莱、罗林逊和罗宾逊等人则分别独立进行了多项实验，试图研究这些宽带所包含的细节内容。XPS的研究由于战争而中止，第二次世界大战后瑞典物理学家凯·西格巴恩和他在乌普萨拉的研究小组在研发XPS设备中获得了多项重大进展，并于1954年获得了氯化钠的首条高能高分辨X射线光电子能谱，显示了XPS技术的强大潜力。1967年之后的几年间，西格巴恩就XPS技术发表了一系列学术成果，使XPS的应用被世人所公认。在与西格巴恩的合作下，美国惠普公司于1969年制造了世界上首台商业单色X射线光电子能谱仪。1981年西格巴恩获得诺贝尔物理学奖，以表彰他将XPS发展为一个重要分析技术所作出的杰出贡献。   基本原理     　　XPS的原理是用X射线去辐射样品，使原子或分子的内层电子或价电子受激发射出来。被光子激发出来的电子称为光电子，通过测量光电子的能量，可以得到丰富的信息。以光电子的动能/束缚能（binding energy，Eb=hv光能量-Ek动能-w功函数）为横坐标，相对强度（脉冲/s）为纵坐标可做出光电子能谱图。光电子的结合能具有指纹效应，可用于鉴别元素及其化学态，并可以对其进行定性和半定量分析。通过结合能的识别得到的谱图可以鉴别元素的组成、化学态的解析（如下谱图所示）。     系统组成 　　一台商业化的XPS系统通常包括以下部分：单色化X射线源系统、真空系统、样品观察和操控系统、光电子探测器、能量分析器、能量传输透镜、电荷中和系统、Ar离子枪、能谱仪控制和数据处理系统、烘烤加热系统、循环水冷却系统、电气控制柜等。随着技术的不断发展，在大面积XPS分析、小面积微区XPS分析、SXI二次电子成像及精准定位、变角XPS分析、深度剖析、低能双束荷电中和等基本功能上，更多的功能可以在XPS系统的基础上得以实现，其中比较常见的功能包括：紫外光电子能谱（UPS）、反光电子能谱（IPES）、离子刻蚀技术（C60、Ar团簇离子枪）、SAM 扫描俄歇能谱、反射式电子能量损失谱（REELS）、样品加热冷却、真空互联等等……   XPS的应用 　　XPS几乎应用于所有表面问题的研究，可定性半定量分析固体材料表面成分信息（包括元素组成、化学态等），并且通过X射线可以进行选区分析从而表征成分的分布情况（ULVAC-PHI扫描聚焦式X射线可小于7.5微米）；所以XPS可被广泛应用于合金、矿物、半导体、高分子聚合物，催化剂、硅酸盐陶瓷、生物医药、能源材料等分析领域。           XPS可以应对从大面积到微区的分析需求，既可以表征表面成分，表面多层薄膜等，又可以对环境颗粒物、表面缺陷（腐蚀，异物，污染，分布不均等）进行微区定位分析，因此对于各种材料开发，材料剖析与失效机理的分析和研究具有不可替代的作用。   小结 　　本文小编粗浅的介绍了X射线光电子能谱仪的一些基础知识，后续我们还会提供更有价值的知识和信息，希望大家持续关注“表面分析家”！   请扫上方二维码关注“表面分析家”公众号     Acknowledgment Thank you XPS International for providing XPS Periodic Table

Hello everyone. We are happy to inform you of the establishment of the Surface Analysis Family.    Please scan the QR code above and follow Surface Analysis Family The formation of this family is based on the goodwill to bring information about surface analysis in terms of the newest technologies, applications, education, publication journal and even market the latest trend. In working in the surface analysis field for tens of years, we feel we have an obligation to make a contribution to try to bring everyone’s knowledge to a higher level. And this is the ultimate will for establishing this platform of the Surface Analysis Family.   The Surface Analysis Family – Target for passing and sharing the related knowledge   The surface analysis had been greatly utilised in the technology and the research field including material properties, organic & inorganic chemicals, metal, polymer, photo-voltaic, battery, environment, semiconductor and many more. From research to actual products, surface analysis has been a critical portion of helping modern technologies to grow. Hence as the final outcome of bringing a better life for humans in the world.   Surface Science can be applied in many different categories, as illustrated in the above picture     Let’s start with the Surface! To start off, let’s start by discussing what is a surface?   A surface, by definition, is an INTERFACE, a marked discontinuity from one material to another. Since no change is ever instantaneous, there is a finite depth for any real surface. In surface analysis, the surface depth is defined by the technique used to characterize it. This depth may vary from an atomic layer, approximately 3-5 Angstrom to as much as 1um.   Surface is like the skin of a person, making all the “first” interactions with others. The above picture had shown such an illustration with also listing the practical importance of the surface of a given solid   In theory, indeed we usually have to start like above the so-called “definition”. However, sometimes it could be easier if we can use some real-life example to express such “definition” for our easy understanding. So if we were to describe the “surface” of some matters in some casual expressions, maybe we can compare it to the skin of a person. Our skin is always the first “interface” to interact with other things or other persons. With such, it could be easy to understand how important is the surface of any matter to play a very important factor. (Well, there is always an advantage for a good looking person)     Let’s look at an example of Surface Analysis Since the surface is so much critical, it makes being able to analyze and characterize it to be an important goal to reach. Below listed some commonly used techniques in surface analysis: Topography     • Visual, Optical Microscopy, SEM… etc.    Elemental/Chemistry     • X-ray Photoelectron Spectroscopy (XPS)     • Auger Electron Spectroscopy (AES)     • Secondary Ion Mass Spectrometry (SIMS)     • EDS, RBS, XRF, FTIR, EELS, RAMAN…. etc.   Take an example from the Auger Electron Spectroscopy, which combined also the SEM function. Below shows an example of how we can characterize a steel sample. The top-middle is the SEM image of the sample surface at 10,000X magnification. The grain structure can be observed. Then a multi-point analysis, shown as point #1~#4, is carried out with the respective Auger analysis spectrum shown. From the spectrum data, it can be easily observed the detecting elements on the 4 selected points are very different. The Auger analysis tool can go 1-step further to perform so-called Auger mapping to show the elemental distribution in a 2-D dimension shown in the bottom-centre image.   The above picture shows an example of Surface Analysis in the case of Auger Electron Spectroscopy (AES) It started from the top-centre SEM image > multi-points analysis with the 4’s Auger energy spectrum and concluded the elemental distribution over a surface by the Auger mapping data     Now we see evidence of how useful is Surface Analysis~ As above mentioned, surface analysis is a proven subject to make a critical contribution to our modern day's technologies as well as a tool for bringing a better life to the world. Certainly, it is impossible to get all information with just one single technique. Rather, there is a number of Surface Analysis techniques which could help in the characterization of the material surface. Below the figure is the very famous SMART chart from EAG, a well-known Analysis company in the world.   A famous and popular Analysis Technique SMART Chart, summarizing various techniques to their detection limit, sampling depth, analytical spot size and so on     Summary Surface Analysis Family on this kicking start will continue to bring more information sharing to everyone. And we are also so much welcome if anyone is/are interested in sharing their knowledge and information with us. Or even if there is a topic you are in question, we will be very happy to hear it from you. Eventually, by building a common Surface Analysis platform here, we vision for all of us that it will benefit all and ultimately continue to make step-up for our Surface Analysis Family.     Background The Surface Analysis Family is initiated by PHI CHINA, a company established in China since 2010. PHI CHINA is the representative for ULVAC-PHI in China. We specialize in surface analysis techniques & instrumentation including XPS, AES, Tof-SIMS and Dynamic SIMS. Members of PHI CHINA are capable of building up a surface analysis instrument to well-utilizing it for producing good data for various applications.   Contact person：张伟 William.Zhang Tel no.: 18500084171 Email：william.zhang@coretechint.com   Surface Analysis Family

Application of X-ray Photoelectron Spectroscopy has seen growth in literary every field of science and technology in recent years due to its unique capabilities of being surface sensitive and providing quantitative elemental and chemical composition.   If we look at which area of applications are using XPS, in particular PHI USA instrumentation, the most are electronics, catalysts, environmental science, polymers, and energy storage. PHI USA instruments provide high throughput needed for metrological measurements of semiconductors, efficient charge neutralization, and spectral resolution required for analysis of polymeric materials, and unique solutions such as controlled atmosphere transfer, in situ cooling and heating, and electrochemical applications needed for a catalytic, battery, and organic electronic materials.   Four areas have the highest percentage growth in XPS application in the last five years – electrocatalysts 1-2 used in alternative fuel cell technologies, perovskites used in organic electronics 3-4 and battery materials5, textiles used as novel materials in stretchable diodes6 and supercapacitors7-8 and pharmaceuticals9.   Figure highlights figures for electocatalyst 1 perovksites3, textile10 and pharmaceuticals9 applications.   References: Morales-Guio, et al.  Nat Catal 1, 764–771 (2018). https://doi.org/10.1038/s41929-018-0139-9 Kim, JY., et al.  Nat Commun 12, 3765 (2021). https://doi.org/10.1038/s41467-021-24105-9 Liu, C., et al.  Nat Commun 12, 6394 (2021). https://doi.org/10.1038/s41467-021-26754-2 Zhang, H., et al.  Nat Commun 12, 3383 (2021). https://doi.org/10.1038/s41467-021-23566-2 Nowroozi, M.A., et al.  Commun Mater 1, 27 (2020). https://doi.org/10.1038/s43246-020-0030-5 Matsuhisa, N., et al. Nature 600, 246–252 (2021). https://doi.org/10.1038/s41586-021-04053-6 Ko, WY., et al.  Sci Rep 6, 18887 (2016). https://doi.org/10.1038/srep18887 Cheng, S., et al.  Sci Rep 7, 6681 (2017). https://doi.org/10.1038/s41598-017-07102-1 Wang, LS., et al. Sci Rep 11, 12410 (2021). https://doi.org/10.1038/s41598-021-91925-6 Deng, X., et al.  Sci Rep 5, 10138 (2015). https://doi.org/10.1038/srep10138        

Since the introduction of PHI XPS, the series of VersaProbe has become the most popular XPS instrument in the world. Last year, PHI had launched the latest fourth-generation XPS: "PHI VersaProbe 4".       The PHI VersaProbe 4 features a newly designed analyzer that enables high sensitivity analysis from tiny to large areas. The unique microfocus scanning X-ray and SXI images can be used as sample navigation through SEM-like SXI images to achieve a 100% accurate definition of the micro-analysis position.   The world's first PHI VersaProbe 4 arrived in China on 21 December 2021. This system also included multiple optional functions on the base XPS. Due to the epidemic and the Chinese New Year holiday, the installation schedule was delayed. The installation ended up to start from early February and the acceptance eventually completed on 14 February this year, taking 2 weeks for the full instrument setup and hand-over training to the customers.   Completion of Installation   The upgrades and highlights of PHI VersaProbe 4: 1. Brand new appearance design   2. Greater sensitivity and resolution for large area analysis   3. Extremely high detection limits   4. Imaging large-area stitching   5. Upgrade of software automation function  

High-quality research publications are at the cornerstone of scientific advancement, understanding, and communication. Here, we review the year 2021 and the impact that the PHI Auger Electron Spectroscopy (AES) instrument has had in supporting scientific breakthroughs.   Over 1300 scholar publications, including peer-reviewed articles and book chapters, have been published in 2021 using PHI AES instruments, many of which were published in high-impact journals (Nature and Science group).   PHI AES instruments were used to study a large range of materials for applications of high technological and research importance - solar cells based on perovskites1, gallium arsenide2, and silicon3 ;  prosthesis and medical implants4-6; 2D materials for quantum electronic devices7; novel catalysts for fuel cells, water splitting, energy storage8-9, and the removal of organic micropollutants10; light emitting diodes11-12; thermoelectric materials13; deep-sea tribocorrosion of metal alloys14; low carbon steels for nuclear power plants and water-cooled reactors15; steel pitting corrosion16; additive manufacturing17; lithium-ion batteries18-19; and all solid-state batteries20.   One paper published this year in Nature Communications as a collaborative study led by the National Engineering Laboratory for Industrial Wastewater Treatment at the East China University of Science and Technology is of impressive scientific merit. This work demonstrates the viability of a naturally abundant Fe/Mn-based catalyst to boost the future development of biomass products such as biofuel and enhance plastics degradation and wastewater treatment. Using the PHI 710 Scanning Auger Nanoprobe, Wang and coworkers21 mapped the fresh and used Mn-based catalyst with a sub-micron spatial resolution to elucidate the mechanism of catalyst oxidation (Figure 1). High spatial resolution (<8 nm) elemental mapping using the PHI 710 instrument enabled superior visualization of this highly topographic material.   Fig. 1: Scanning Auger mapping of Mn of fresh (bottom) and used (top) MnO2/Goe catalyst   Another esteemed paper published this year in NPG Asia Materials by Haindl and coworkers22 at the Tokyo Institute of Technology and the University of Glasgow utilizes the PHI 710 Auger instrument to study Fe-based superconductors. In this work, the interface chemistries of Fe-pnictide heterostructure layered materials were probed via Auger depth profiling. The Auger depth profiles reveal smooth and clean interfaces in undoped and Co2+ substituted cases, and an interface layer formation present in the case of excess O2- during deposition (Figure 2). The ability to precisely depth profile these extremely thin layers highlights the capabilities of the monoatomic Ar+ ion gun equipped on the PHI 710 and demonstrates minimal sputter mixing and enhanced depth resolution.   Fig. 2: STEM images of a. clean, undoped Sm-1111/Ba-122 interface, b. clean, Co2+-substituted La-1111/Ba-122interface; c. interface layer (IFL) formation in Sm-1111/Ba-122 with excess O2–.  AES depth profiles across the interface for d. undoped Sm-1111/Ba-122, e. Co2+-substituted La-1111/Ba-122, and f. Sm-1111/Ba-122 with excess O2–   A third high-impact publication this year in Electrochemica Acta by Zhao and coworkers23 uses the PHI 710 Scanning Auger Nanoprobe to study Na-ion battery materials. In this work, the stability and performance of Na-ion battery technology was enhanced via surface modification of sodium manganese hexacyanoferrate (NaMnHCF) as a cathode material. Auger spectroscopy was used to analyze the in-depth chemical composition of the modified surface. The spectra reveal an increase in Cu composition and a decrease in Mn composition after sputtering ~20 nm into the material. This modification significantly improves the long-term stability of the electrode.   Fig. 3: In-depth AES spectra of Mn and Cu on a microscale grain of NaMnHCF after the ion-exchange modification   PHI CHINA is proud of the role the PHI 710 Scanning Auger Nanoprobe has played in achieving such prestigious scientific advancements over this past year. Please visit the citations below for more details regarding the studies mentioned in this article. https://doi.org/10.1021/acsomega.1c05002 https://doi.org/10.1016/j.apsusc.2021.149205 https://doi.org/10.1016/j.optmat.2021.111291 https://doi.org/10.1116/6.0001233 https://doi.org/10.1016/j.cej.2021.133940 https://doi.org/10.1002/jbm.b.34781 https://doi.org/10.1126/sciadv.abk1892 https://doi.org/10.1002/adfm.202107058 https://doi.org/10.1016/j.electacta.2021.139266 https://doi.org/10.1016/j.ceja.2021.100214 https://iopscience.iop.org/article/10.1088/2053-1591/ac3fdd/meta https://doi.org/10.1039/d1nr04220c https://doi.org/10.2320/matertrans.E-M2021812 https://doi.org/10.1016/j.corsci.2020.109185 https://doi.org/10.3103/S0967091221070068 https://doi.org/10.3390/met11030428 https://doi.org/10.1117/12.2601291 https://doi.org/10.1016/j.jpowsour.2021.229573 https://doi.org/10.3390/batteries7040065 https://doi.org/10.1002/aenm.202101370 https://doi.org/10.1038/s41467-021-27240-5 https://doi.org/10.1038/s41427-021-00336-6 https://doi.org/10.1016/j.electacta.2021.138842

We are looking back at the impact of PHI TOF-SIMS instruments in supporting scientific publications in the year 2021. Over 900 scholar publications, including peer-reviewed articles and book chapters, have been published in 2021 using PHI nanoTOF instruments. PHI TOF-SIMS instruments were used to study a large range of materials for applications of high technological and research importance - solar cells based on perovskites1-3, 2D materials4, biological materials5,6, and batteries.7-9   Here we would like to highlight a few papers that demonstrate the unique capabilities of PHI nanoTOF instruments.   In the first paper published in Nature (cited 6 times in the first year), our customers from New York University Tandon School of Engineering used a PHI nanoTOF II instrument as well as a PHI VersaProbe to study perovskite based solar cells1. They conducted TOF-SIMS depth profiling to demonstrate how reducing the content of lithium ions in the hole-transporting layers (HTL) lowered the overall content in the vertical device direction. “Lithium ions intercalating into the perovskite active layer can result in decomposition of the perovskite and formation of metallic lead, creating recombination sites. The lithium ions were concentrated in particular in the bottom contact layers (Figure 1a), which has been shown to result in device failure.” Authors demonstrated that carbon dioxide doping results in a device in which lithium-ion signal is much lower with a minimum accumulation of lithium ions in the bottom contact layers (Fig. 1b)   Fig. 1 TOF-SIMS depth profile of pristine solar cell (a) and CO2-treated layer (b)   Another paper published in Advanced Electronic Materials is focused on functionalization of 2D materials, such as MoS2 and WSe2.4 Authors from the University of Bundeswehr combined atomic force microscopy-infrared (AFM-IR) spectroscopy and monolayer sensitive TOF-SIMS, to “overcome the limitations of classical surface analysis and prove the highly selective functionalization of the 2D material surface, which is preferred over the substrate.” In Figure 2, the elemental maps of negative secondary ions 32S−, 28Si−, O−, C−, CH−, and CH2− were collected from a single, clearly distinguishable, PBI functionalized, and CVD-grown MoS2 flake on a SiO2/Si substrate. This paper highlighted the great potential of unconventional techniques such as TOF-SIMS in the field of 2D materials and organic SAMs.   Fig. 2 High resolution TOF-SIMS maps of 32S−, 28Si−, O−, C−, CH−, and CH2− secondary ions   Fig. 3 ToF-SIMS results of bare and hydroxyapatite coated cathode powders, (d) positive fragments: LiOH+, LiOH2+, LiCO2+, (e) negative fragments: CaPOH3−, LiCaPO−, LiCaPOH− fragments (top: bare; bottom: coated) (f) Schematic illustration for the detailed modification process   The third paper we would like to highlight is published by authors from Small Engineering & Sejong Battery Institute and focuses on improving stability of Ni-rich cathodes for lithium-ion batteries. The authors used hydroxyapatite as a coating material, which showed excellent chemical and mechanical properties that provide a suitable coating medium for Ni-rich cathode materials. LiOH+ (m/z = 24.01), LiOH2+ (m/z = 25.01), and LiCO2+(m/z = 51.00) fragments, corresponding to the residual lithium compounds, emerged to be significantly high for the bare material relative to the coated materials (Figure 3d). Fragments from lithium-doped hydroxyapatite were also detected (Figure 3e). These fragments were not observed for the uncoated cathode. In addition, TOF-SIMS was used to study the surface of the coating after electrochemical reaction for 500 and 1000 cycles. The formation of fluorinated Ca4.67Li0.33(PO4)3F and CaF2 layers was found to be related to morphological stability.   Read more about these and other discoveries in the papers cited below. https://doi.org/10.1021/acsami.1c15505 https://www.nature.com/articles/s41586-021-03518-y#Sec26 https://onlinelibrary.wiley.com/doi/abs/10.1002/aenm.202101454 https://doi.org/10.1038/s41566-021-00857-0 https://doi.org/10.1002/aelm.202000564 https://doi.org/10.1038/s41598-021-92044-y https://doi.org/10.1038/s41598-020-78416-w https://doi.org/10.1002/smll.202104532 https://doi.org/10.1116/6.0001044 https://doi.org/10.1016/j.ensm.2021.11.017  

Publishing recent discoveries in science and technology in peer-reviewed literature is a critical function of members of the research community. It enables us to recognize the latest progress and inspires further advances. We are looking back onto the year 2021 – on the impact Physical Electronics XPS instruments, such as  PHI VersaProbe,  PHI Quantera, and PHI Quantes, have had in supporting scientific breakthroughs.   Over 4500 scholar publications, including peer-reviewed articles and book chapters, have been published in 2021 using PHI XPS instruments. There were more than 60 papers published in the high-impact journals (Nature and Science group), with more than 30% studying novel energy-related materials, such as batteries, fuel cells, and solar cells, and 20%. on nanomaterials.   PHI XPS instruments were used to study a large range of materials of high technological and research importance -  surface treatment for inactivating SARS-CoV‑2 Virus1, oxygen evolution electrocatalysts2,3, CO2 reduction catalysts4, single-atom catalysts5,6, graphene-based materials for electrochemical materials7, ion-selective biological channels8, perovskite solar cells9,10, novel 2D materials – MXenes11 and magnetene12, novel magnetic materials based on perovskites for cooling applications13, organic multilayered semiconductors14, next-generation cathodes for lithium batteries15,16, 17, sodium-ion batteries18, lithium-ion batteries19 and solid-state batteries20.   One paper with the highest number of citations (51 citations in less than one year) published in ACS Nano is from our customers at Drexel University studying novel types of 2D materials - highly conductive Ti3C2 MXene.11 “MXenes have been utilized in various fields, including energy storage and conversion, electromagnetic interference shielding, nanocomposites, sensors, and biomedical applications. MXenes have several significant advantages over graphene and many other conducting nanomaterials: MXenes form stable colloidal solutions without additives or surfactants, and they can easily be processed using the cheapest and safest solvent−water”.  Using the PHI VersaProbe Scanning XPS Mircoprobe instrument, Mathis and co-workers demonstrated close to perfect stoichiometry and elimination of oxygen from the carbon sublattice, which may have contributed to the improved oxidation stability of the Al−Ti3C2.   XPS is becoming one of the main characterization techniques scientists use in their discovery of novel battery materials. In a collaborative work led by the Massachusetts Institute of Technology (published in Nature Energy and cited 16 times in less than a year17), a novel sulfonamide-based electrolyte was shown to enable stable ultra-high-voltage cycling of a high-nickel cathode in practical Li metal batteries. To characterize the cathode-electrolyte interface, XPS measurements were conducted on the surface of the cathodes after the 100 cycles. Authors compared C 1s, and F 1s spectra from a cathode cycled in the novel electrolyte to that in a reference and discovered more  LiF-like inorganic components and less organic components pointing to the less reactive and corrosive nature of the novel electrolyte.   Fig. 1 XPS analysis for the cathodes cycled in the novel sulfonamide-based electrolyte (f and h) and reference (e and g) electrolytes for 100 cycles. PVDF= polyvinylidene fluoride   Another important collaborative work between researchers at Zhengzhou University, Penn State University, and the University of Texas at Austin (published in Nature communication and cited nine times in less than a year21) focuses on lithium-sulfur (Li–S) batteries that couple a Li anode with a sulfur (S) cathode. Authors address two significant problems in Li-S batteries - interfacial instability of the lithium-metal anode and polysulfide migration from the cathode - by using a promising electrolyte additive BTT, which involves an exchange reaction on the Li-metal anode and electrochemical polymerization on the sulfur cathode.   Fig. 2 XPS data for the recharged cathode after 5 cycles at 0.05C rate for the BTT cell (top), and the discharged cathode after 5 cycles for BTT cell (bottom) They used the PHI VersaProbe instrument for depth profile characterization of the dual solid-electrolyte interface in asymmetric Li cell after cycling. The depth profile provided information on the chemical environment between Li and the S-H functional group of BTT based on the Li, S, and F spectra. The homogeneity of Li3-BTT and the apparent change of Li-F demonstrated that the BTT SEI is composed of organic lithium and inorganic lithium compounds. “Compared with the BTT electrode, the SEI formed in the commercial electrolyte is fragile and has poor ionic conductivity, with uneven composition. It also includes more reduced products, such as SO32- and S2- (from LiTFSI) in the S 2p spectrum and side reaction products of LiOH (55.0 eV in Li 1s spectrum), Li–O, and Li–F in the Li 1s spectrum.”   XPS was also collected to further understand the chemical composition of the charged product. The S 2p peaks of the bridged S (S–S) and the S bonded to the phenyl ring (C-S) are found at 164.1 eV and 163.5 eV in the recharged product, respectively. The presence of Li2S and Li2S2 are due to the incomplete charging of the cell.   We are very proud to be a part of the exciting discoveries our customers make. Read more about them in the papers cited below. https://doi.org/10.1021/acsami.1c15505 https://doi.org/10.1038/s41560-021-00925-3 https://doi.org/10.1002/adfm.202106229 https://doi.org/10.1038/s41467-021-25573-9 https://www.science.org/doi/10.1126/sciadv.abd9210 https://doi.org/10.1038/s41557-021-00734-x https://doi.org/10.1038/s41598-021-01154-0 https://doi.org/10.1021/acsnano.1c07210 https://doi.org/10.1038/s41467-021-26754-2 https://doi.org/10.1038/s41565-021-01010-2 https://doi.org/10.1021/acsnano.0c08357 https://www.science.org/doi/10.1126/sciadv.abk2041 https://doi.org/10.1038/s41598-021-99755-2 https://doi.org/10.1002/smtd.202001264 https://doi.org/10.1021/acsami.1c15271 https://doi.org/10.1038/s41467-021-26815-6 https://doi.org/10.1038/s41560-021-00792-y https://doi.org/10.1002/adfm.202109694 https://doi.org/10.1038/s41467-021-26073-6 10.33774/chemrxiv-2021-4dnn0 https://doi.org/10.1038/s41467-021-23155-3      

On November 5th, 2021, PHI China had successfully held the "ULVAC-PHI Surface Analysis Application and Academic seminar User Meeting (Guangdong)" at Shenzhen, Guangdong. This meeting focused on the application of surface analysis and its technology. Many experts and professors were invited to exchange reports. This conference was not only an offline communication, but also conducted an online report live broadcast, which attracted the participation of many online and offline universities and enterprises, and a good academic exchange atmosphere has been established.   With the rapid development of high and new technology in the fields of materials, energy, microelectronics, information industry and environment, surface science has become one of the most active disciplines in the world, and the demand for surface analysis technology is also increasing. XPS/TOF-SIMS/AES have all become effective surface analysis techniques, and are widely used in basic scientific research, advanced material development, high-precision technology and other fields, which has promoted the research and development of materials science. This conference not only interpreted some of the current statuses, problems and challenges of the surface analysis industry from a macro perspective, but also introduced and shared the application and case studies of surface analysis instruments. Combining theory with practice, face-to-face exchanges and discussions were on-site.   Group photo   Professor of Sun Yat-sen University  Mr. Jian Chan   Professor of Southern University of Science and Technology  Mr. Ding Sun An     Professor of Institute for Advanced Study, Shenzhen University  Mr. Zhao Wei   Engineer of Southern University of Science and Technology  Ms. Zhang Juan   Senior Engineer of SAE Technologies Development (Dongguan) Co., Ltd.  Ms. Wang Mu    Executive Director of PHI (China)  Mr. Wensly Yip   PHI CHINA will uphold its original aspiration and continue to help the development of the surface analysis industry. In the future, we will continue to hold more online and offline seminars, so please stay tuned!   You may watch back the video by accessing Technical Info > Technical video