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Seminar Reminder for Xianyi Hu's Ph.D. Final Exam. Seminar, Tuesday, July 16, at 9:00 a.m., in ARMS 1028. Exam same day at 10:00, in ARMS 2237. "Solution Processing of Silver-based Kesterite: from Nanoparticles to Thin Film Solar Cells"
by Son, Rosemary E 15 Jul '19

15 Jul '19

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Solution Processing of Silver-based Kesterite: from Nanoparticles to Thin Film Solar Cells" By Xianyi Hu Purdue MSE Ph.D. Final Exam Advisors: Professor Carol Handwerker and Professor Rakesh Agrawal ABSTRACT Because of the limited reserve of fossil fuels and issues brought up by their combustion, the demand on renewable energy is considerably increasing. Solar energy is one of the most promising renewable energy sources considering the large amount of solar irradiation received by Earth and solar cell is such a device that allows us to directly convert sunlight directly into electricity. In this thesis, kesterite (I2-II-IV-IV4) system is the main focus as the light absorber material in thin film solar cells. Cu2ZnSn(S,Se)4 (CZTSSe) has been first studied. However, due to the band tailing resulted from Cu-Zn anti-site defects, further improvement on power conversion efficiency of this material is hindered. Substituting Cu with Ag is expected to solve this problem by decreasing this defect density as a result of the high formation energy of Ag-Zn anti-site defects. Herein, different concentration of Ag is used to substitute Cu in the kesterite system through nanoparticle-ink route for the fabrication of light absorber thin films. For Ag-alloying concentration less than 50%, it suggests that the Ag can induce inhomogeneity, secondary phase formation during nanoparticle formation. Moreover, Ag-alloying is shown to enlarge the grain size and reduce film roughness after selenization, which are beneficial for the optoelectronic properties and device performance. Additionally, the synthesis process for kesterite Ag2ZnSnS4 nanoparticles is explored. AZTS nanoparticles are achieved by solvent-thermal reaction. The reaction pathway during reaction is investigated by different material characterization methods to shed light on the Ag-based nanoparticle synthesis. The final obtained nanoparticles have high crystallinity and homogeneous composition, demonstrating great potential as light absorber materials. Furthermore, the sulfide nanoparticles are converted into selenide thin films in Se vapor at elevated temperature (selenization). The selenization conditions, as well as other process parameters, are optimized for the pure phase kesterite AZTSe thin films with large and dense grains. The optoelectronic properties are explored on these films and an initial research already demonstrates a 0.35% power conversion efficiency as the first solution processed AZTSe device. In summary, multiple material characterization techniques are utilized to understand the microstructure evolution, phase transformation and composition change for solution-processed nanoparticles and following thin films. The material characteristics, process methods and film optoelectronic properties are associated for the future analysis and development of kesterite thin films for photovoltaic applications. Date: Tuesday, July 16, 2019 Time: 9:00 A.M. Place: ARMS 1028

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Microsoft Outlook Calendar Issues
by Stacey, Lisa A 12 Jul '19

12 Jul '19

Please see the following message and link for status on the Microsoft Outlook Calendar issues we have been experiencing this week: There is an ongoing issue - ITAP is working on it - this page contains the status: https://support.purdue.edu/MRcgi/MRTicketPage.pl?USER=&PROJECTID=17&MR=1135… Last we heard ITAP was working with Microsoft. Lisa Stacey Administrative Assistant to the Department Head Purdue University School of Materials Engineering Neil Armstrong Hall of Engineering 765/494-4095 staceyl(a)purdue.edu [https://www.purdue.edu/brand/images/Purdue_University-150_Years_of_Giant_Le…]

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boxes and packing materials
by Coar, Stacey L 12 Jul '19

12 Jul '19

Good morning all, I am moving over the next week and I need more boxes and packing material. If you have any boxes, peanuts, bubble wrap or anything like this that you would like to get rid of in your lab or office, I would be happy to take it off your hands. You can bring them to my desk in ARMS 2300 or email me where I can come and pick them up I will be glad to do so. Thank you and happy Friday, Stacey Stacey Coar Secretary/Development Assistant School of Materials Engineering Purdue University Neil Armstrong Hall of Engineering 701 West Stadium Ave. Room 2300 West Lafayette, IN 47907 765-494-4100 scoar(a)purdue.edu<mailto:scoar@purdue.edu>

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Today: Workshop July 12, 2019 on Multiphase Diffusion
by Coar, Stacey L 12 Jul '19

12 Jul '19

[cid:image001.jpg@01D53890.43C6B640] Stacey Stacey Coar Secretary/Development Assistant School of Materials Engineering Purdue University Neil Armstrong Hall of Engineering 701 West Stadium Ave. Room 2300 West Lafayette, IN 47907 765-494-4100 scoar(a)purdue.edu<mailto:scoar@purdue.edu>

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Seminar Notice for Matthew Michie's Ph.D. Final Exam. Seminar Wednesday, July 17, at 9:00 a.m., in ARMS 3109; Exam same day at 10:00, in ARMS B197 "Grain Growth Rate Transitions in Barium Strontium Titanate"
by Son, Rosemary E 10 Jul '19

10 Jul '19

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Grain Growth Rate Transitions in Barium Strontium Titanate" By Matthew J. Michie Purdue MSE Ph.D. Final Exam Advisors: Professor Carol A. Handwerker and Professor John E. Blendell ABSTRACT Understanding grain growth of dielectric ceramics is essential to controlling the electrical and mechanical properties necessary to produce ceramic capacitors and sensors. The effect of alloying barium titanate with strontium titanate on the equilibrium crystal shape is being investigated in order to determine possible impacts on grain growth. The equilibrium crystal shape is being studied through three experimental methods to identify possible changes in the mobility or driving force with changing composition. The first method is by imaging intergranular pores to observe faceting behavior and relative interfacial energies. The second method is to perform atomic force microscopy on surface facets to collect topography data. The topography data is combined with orientation data obtained by EBSD analysis from the same region and is used to calculate the normal vector of the surface facets. The normal vectors are plotted in a stereographic projection to verify the faceting relationships observed in the pore shape analysis. The third method involves collecting EBSD orientation data and images of surface faceting behavior. The surface faceting behavior of each grain is categorized by type of facet and plotted on a stereographic projection at the corresponding orientation. This allows for the analysis of faceting transitions and the differentiation of faceted and continuous regions of the equilibrium crystal shape. The analysis of the equilibrium crystal shape of across compositions has implications on grain growth of the barium titanate/strontium titanate system. Date: Wednesday, July 17, 2019 Time: 9:00 A.M. Place: ARMS 3109

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Seminar Notice for Xianyi Hu's Ph.D. Final Exam. Seminar, Tuesday, July 16, at 9:00 a.m., in ARMS 1028. Exam same day at 10:00, in ARMS 2237. "Solution Processing of Silver-based Kesterite: from Nanoparticles to Thin Film Solar Cells"
by Son, Rosemary E 09 Jul '19

09 Jul '19

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Solution Processing of Silver-based Kesterite: from Nanoparticles to Thin Film Solar Cells" By Xianyi Hu Purdue MSE Ph.D. Final Exam Advisors: Professor Carol Handwerker and Professor Rakesh Agrawal ABSTRACT Because of the limited reserve of fossil fuels and issues brought up by their combustion, the demand on renewable energy is considerably increasing. Solar energy is one of the most promising renewable energy sources considering the large amount of solar irradiation received by Earth and solar cell is such a device that allows us to directly convert sunlight directly into electricity. In this thesis, kesterite (I2-II-IV-IV4) system is the main focus as the light absorber material in thin film solar cells. Cu2ZnSn(S,Se)4 (CZTSSe) has been first studied. However, due to the band tailing resulted from Cu-Zn anti-site defects, further improvement on power conversion efficiency of this material is hindered. Substituting Cu with Ag is expected to solve this problem by decreasing this defect density as a result of the high formation energy of Ag-Zn anti-site defects. Herein, different concentration of Ag is used to substitute Cu in the kesterite system through nanoparticle-ink route for the fabrication of light absorber thin films. For Ag-alloying concentration less than 50%, it suggests that the Ag can induce inhomogeneity, secondary phase formation during nanoparticle formation. Moreover, Ag-alloying is shown to enlarge the grain size and reduce film roughness after selenization, which are beneficial for the optoelectronic properties and device performance. Additionally, the synthesis process for kesterite Ag2ZnSnS4 nanoparticles is explored. AZTS nanoparticles are achieved by solvent-thermal reaction. The reaction pathway during reaction is investigated by different material characterization methods to shed light on the Ag-based nanoparticle synthesis. The final obtained nanoparticles have high crystallinity and homogeneous composition, demonstrating great potential as light absorber materials. Furthermore, the sulfide nanoparticles are converted into selenide thin films in Se vapor at elevated temperature (selenization). The selenization conditions, as well as other process parameters, are optimized for the pure phase kesterite AZTSe thin films with large and dense grains. The optoelectronic properties are explored on these films and an initial research already demonstrates a 0.35% power conversion efficiency as the first solution processed AZTSe device. In summary, multiple material characterization techniques are utilized to understand the microstructure evolution, phase transformation and composition change for solution-processed nanoparticles and following thin films. The material characteristics, process methods and film optoelectronic properties are associated for the future analysis and development of kesterite thin films for photovoltaic applications. Date: Tuesday, July 16, 2019 Time: 9:00 A.M. Place: ARMS 1028

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Workshop July 12, 2019 on Multiphase Diffusion
by Coar, Stacey L 08 Jul '19

08 Jul '19

[cid:image001.jpg@01D53590.87EDA980] Stacey Stacey Coar Secretary/Development Assistant School of Materials Engineering Purdue University Neil Armstrong Hall of Engineering 701 West Stadium Ave. Room 2300 West Lafayette, IN 47907 765-494-4100 scoar(a)purdue.edu<mailto:scoar@purdue.edu>

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Seminar Notice for Qi Wang's Preliminary Exam. Seminar, Monday, July 8, at 1:30 pm, in ARMS 1028. Exam same day, at 3:00, in ARMS 2326. " Resistive Switching and the Future in Perovskite Nickelates"
by Son, Rosemary E 05 Jul '19

05 Jul '19

Please consider attending the following: MATERIALS ENGINEERING SEMINAR "Resistive Switching and the Future in Perovskite Nickelates" By Qi Wang Purdue MSE Preliminary Exam Advisor: Professor Shriram Ramanathan ABSTRACT The resistive switching behavior has attracted lots of attention recently, due to the potential of application in non-volatile memory devices. An electroforming process as a pretreatment is usually necessary and critical. A wide range of materials have been studied, which are mostly transition metal oxides. Resistive switching can be either bipolar switching or unipolar switching depending on the switching mechanisms. There are two main mechanisms: One is conduction filaments formation and rupture inside materials, the other is the interfaces-type resistive switching because of the barrier or junction between oxide layers and metal electrodes. Many perovskite rare earth nickelates (RENiO3) exhibit a sharp metal-insulator transition when temperature decreases. This thermally driven transition can be explained by charge disproportionation between two adjacent NiO6 octahedrons. Electron doping can also induce such a metal-insulator transition by reducing Ni3+ into Ni2+. We found SmNiO3 and NdNiO3 showed an enormous resistance increase at room temperature after hydrogenation due to electron doping and valency change. It has been proved that the resistance of H-NdNiO3 is able to switch under certain electrical operations, with controllable resistance states as wells as low energy cost. Date: Monday, July 8, 2019 Time: 1:30 PM Place: ARMS 1028

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[TODAY] Sandia seminar and recruitment opportunity
by Coar, Stacey L 27 Jun '19

27 Jun '19

Dear all, This is a reminder about the Sandia seminar today. 1:30 PM, Thursday, June 27, 2019 Seng-Liang Wang Hall, Room 1004 Please see below for a seminar and recruitment event from Sandia National Laboratories. You may be aware that Sandia National Laboratories is hiring a large number this next year. Dr. Nowlin is looking for a few potential candidates for staff positions in microelectronics technology development, reliability or radiation effects. If interested, you will have the opportunity to speak to Dr. Nowlin after his seminar. ----------------------------------------------------------------- Advanced Microsystems Radiation Effects R&D at Sandia National Laboratories Dr. Nathan Nowlin Sandia National Laboratories 1:30 PM, Thursday, June 27, 2019 Seng-Liang Wang Hall, Room 1004 Sandia National Laboratories (SNL) develops advanced technologies to ensure global peace. We are called upon by our Nation to conduct leading-edge national-security research in the physics, modeling, hardening, and hardness assurance, and development of advanced microsystems, microelectronics, photonics, optoelectronics, micro-electrical-mechanical, and heterogeneously integrated circuits in Silicon CMOS, compound semiconductors and other materials and devices in harsh radiation environments. Dr. Nowlin, from the Advanced Microsystems Radiation Effects department, will describe recent research his team has reported on the development of radiation hardened technologies manufactured at SNL, as well as new work in the radiation hardness assurance of advanced integrated circuits from leading commercial manufacturers. Dr. Nathan Nowlin has 25 years experience in advanced microelectronics and radiation effects research. In his early career, he co-discovered the Enhanced Low Dose Rate Sensitivity (ELDRS) effect in bipolar transistors. He then spent several years in the semiconductor industry developing high voltage Lateral Drain MOS (LDMOS) process technology and leading yield engineering for a high-speed BiCMOS technology. In the early 2000’s, he went to work for Mission Research Corporation, where he led the development of a 90nm Radiation Hardened By Design (RHBD) library and SRAM compiler for spacecraft Application Specific Integrated Circuit (ASIC) designs. In his 10 years at Sandia, Dr. Nowlin has led research and development efforts for radiation hardening by design, advanced circuit modeling of radiation effects, and product engineering for high reliability, high consequence systems. Dr. Nowlin was a product realization team lead for 10 ASIC products, developing requirements, demonstrating prototypes, and initiating production for all aspects from wafer manufacturing, packaging, test, reliability, and radiation performance. His efforts enabled Sandia to successfully begin its largest ASIC production mission in its history. Dr. Nowlin now leads the Advanced Microsystems Radiation Effects department where he is responsible for trust and radiation hardness assurance of microsystems for national security applications. Dr. Nowlin is a Senior Member of the IEEE Nuclear and Plasma Sciences Society (NPSS), has authored or co-authored 21 papers, and serves on the organizing committees for the Nuclear and Space Radiation Effects Conference (NSREC) and the Hardened Electronics And Radiation Technologies (HEART) technical interchange meeting. Xufeng

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Workshop today on Analytical solution of diffusion equation- ARMS 1028/11:30
by Coar, Stacey L 26 Jun '19

26 Jun '19

From: Coar, Stacey L Sent: Monday, June 24, 2019 11:02 AM To: 'msefaculty-list(a)ecn.purdue.edu' <msefaculty-list(a)ecn.purdue.edu>; 'msegradstudent-list(a)ecn.purdue.edu' <msegradstudent-list(a)ecn.purdue.edu>; 'msepostdoc-list(a)ecn.purdue.edu' <msepostdoc-list(a)ecn.purdue.edu> Subject: Workshop starting today on Diffusion in Solids with an Emphasis on Multicomponent Diffusion Importance: High [cid:image001.jpg@01D52C0D.07B5F560] Stacey Stacey Coar Secretary/Development Assistant School of Materials Engineering Purdue University Neil Armstrong Hall of Engineering 701 West Stadium Ave. Room 2300 West Lafayette, IN 47907 765-494-4100 scoar(a)purdue.edu<mailto:scoar@purdue.edu>

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