January 2013 - BNC-all - ecn.purdue.edu

Physics colloquium today - Dr. Claire Gmachl
by Turner, Jaime J 31 Jan '13

31 Jan '13

Physics Colloquium Claire Gmachl Dept. of Electrical Engineering & MIRTHE at Princeton University "Mid-Infrared Quantum Cascade Lasers" Thursday January 31, 2013 4:00pm PHYS203 Refreshments are served at 3:30 p.m. in Physics room 242 Quantum Cascade (QC) lasers are a rapidly evolving mid-infrared and THz, semiconductor laser technology based on intersubband transitions in multiple coupled quantum wells. The lasers’ strengths are their wavelength tailorability, high performance and fascinating design potential. We will first give a brief introduction into QC lasers followed by a discussion of several recent highlights, such as the quest for high performance QC lasers, especially high efficiency and single-mode operation, and the implementation of unconventional laser schemes. We will also discuss several applications, such as our field campaigns during the 2008 Beijing Olympics and in Ghana in 2009 and 2010. As an example for high-performance QC lasers, we examine lasers around 5 mm wavelength. First, we focus on thorough engineering of conventional QC lasers. The quest for high power and high efficiency QC lasers requires these lasers to have a low intrinsic threshold, a high characteristic temperature, a low voltage defect, and superior heat sinking. QC lasers with several percent wall-plug efficiency at room temperature and few 10% efficiency at low temperatures are possible. Next, we move on to unconventional designs, and a recent innovation in how the carrier injection into QC laser active regions is described. The resultant QC lasers are nearly 50% power efficient at cryogenic temperatures. With respect to spectral innovations, a spectrally broadband QC laser based on a ‘continuum-to-continuum’ design will be presented, which differs from conventional, artificially spectrally broadened QC lasers in that almost no trade-off needs to be made between gain-bandwidth and laser performance with respect to laser threshold and output power. When this laser is put into an external cavity, a wide, continuous single-mode tuning range of well over 300 cm-1 is achieved. Next we explore opportunities for obtaining single-mode and tunable emission without the need of dispersive gratings, such as external dispersive cavities or gratings etched int o the lasers.. Folded cavities, “candy-cane“-shaped lasers, and extreme multi-section lasers have all shown great potential for achieving single-mode emission at reduced fabrication complexity and cost. In summer 2008 we deployed two QC laser-based trace gas sensors for air-quality measurements in Beijing, China, one point-sensing and one open-path remote sensing instrument for the detection of common air pollutants. During the summers of 2009 and 2010, we deployed an improved version of the open-path sensing instrument in Elmina, a fishing village in Ghana, to detect air toxics from wood burning and fish smoking. The work presented is mostly supported by MIRTHE (NSF-ERC) with smaller contributions from other sources; the work has been conducted in collaboration with many valued colleagues in our own research group and across MIRTHE. Claire Gmachl received the Ph.D. degree (sub auspicies praesidentis) in electrical engineering from the Technical University of Vienna, Austria, in 1995. In 1996, she joined Bell Laboratories, Lucent Technologies, Murray Hill, NJ, as Post-Doctoral Member of Technical Staff to work on Quantum Cascade laser devices and microcavity lasers. In March 1998 she became a Member of Technical Staff in the Semiconductor Physics Research Department and a Distinguished Member of Staff in 2002. In September 2003, Gmachl joined Princeton University as an Associate Professor in the Department of Electrical Engineering and adjunct faculty to PRISM; since July 2007 she is Full Professor at Princeton University, and a Eugene Higgins Professor of Electrical Engineering since 2011. Her group’s research is focused on mid-infrared photonics, especially high performance and innovative Quantum Cascade lasers, semiconductor band-structure engineering, and novel materials for the mid-infrared. Gmachl is the Director of MIRTHE, the NSF Engineering Research Center on Mid-InfraRed Technologies for Health and the Environment, established in 2006. This six-university center develops mid-infrared trace-gas sensors for applications in the environment, health, and security through a cross-disciplinary approach that spans from applications and policy, to systems engineering, device development, and material science. Gmachl has authored and co-authored more than 200 publications, has given more than 100 presentations at conferences and seminars, and holds 26 patents. She has won an E-council/GEC Excellence in Teaching Award in 2012, and a Princeton University graduate mentoring award in 2009; she was an Associate Editor for Optics Express and a member of the IEEE/LEOS Board of Governors. Gmachl is a 2005 MacArthur Fellow. She is a member of several professional societies. Oana Malis Assistant Professor Department of Physics Purdue University 525 Northwestern Ave. West Lafayette, IN 47907 Phone: (765) 494-3039 Fax: (765) 494-0706 email: omalis(a)purdue.edu

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Hot chocolate at 2pm in BRK kitchen
by Manuel Ochoa 28 Jan '13

28 Jan '13

Dear Birck grad students, staff, and faculty, The Nanotechnology Student Advisory Council (NSAC) would like to invite you for Hot Chocolate today at 2PM in the BRK kitchen. Come relax and chat for a few minutes while drinking some delicious hot chocolate. We hope to see you there! NSAC

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Preliminary examination announcement - Sambit Palit
by Sambit Palit 28 Jan '13

28 Jan '13

Dear all, You are invited to the presentation for my Preliminary exam, the details of which are as follows. Coffee and cookies will be provided. Title: Charging and Transport in Amorphous Dielectrics and Reliability Implications for RF-MEMS Date: 01/29/2013 Time: 02:00 PM Venue: BRK 1001 Abstract: Thin film dielectrics have broad applications, and the performance degradation due to charge trapping in these thin films is an important and pervasive reliability concern. Historically, charge transport through dielectrics has been presumed to be either bulk dominated (Frenkel-Poole (FP) emission) or to be contact dominated (Fowler-Nordheim tunneling), dependent on the dielectric thickness. We develop a comprehensive dielectric charging modeling framework which solves for the transient and steady state charge accumulation and leakage currents in an amorphous dielectric, and show that for most thin film dielectrics in commercial use, the conventional assumption of FP dominated current transport is incorrect, and may lead to false extraction of dielectric properties. In order to correctly characterize dielectrics from their steady state leakage current characteristics, we propose an improved technique based on an analytical approximation of the dielectric charging model. We further show that our model replicates measured transient leakage characteristics in Silicon Nitride more accurately, given defect energy levels are known from first-principles calculations. Next, we study Radio Frequency Microelectromechanical Systems (RF-MEMS) capacitive switches as one of the target applications of these thin film dielectrics. Charge accumulation in dielectrics in RF-MEMS capacitive switches result in temporal shifts in actuation voltages, eventually resulting in failure due to stiction. Analysis and design of electromechanical actuators has historically been done on a case-by-case basis. We propose fundamental scaling relationships in electromechanical actuators in general, which are independent of specific physical dimensions and material properties. The scaling theory offers an intrinsic classification of all electromechanical actuators and consequently reduces the problem of analysis/design of complex electromechanical actuators to determining a few scaling parameters associated with specific geometry-classes. Finally, we propose a novel fully electronic, resonance based characterization technique for RF-MEMS capacitive switches to quantify degradation due to dielectric charging, which overcomes several limitations in conventionally used methods. The proposed technique also opens up possibilities for large scale parallelization for technology qualification and in-situ electronic degradation monitoring. In the future, we wish to generalize the theory of dielectric charging and degradation physics to polymer dielectrics. Even though polymer dielectrics are widely used as inter-layer dielectrics, diffusion barriers and passivants in conventional fabrication processes, their degradation is often modeled empirically. The techniques developed in this preliminary report will help explain and solve some of the long standing puzzles in this field.

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BNC E-news
by Anthrop, Heather L 25 Jan '13

25 Jan '13

Tuesday, January 29th Sambit Palit Final Exam Birck 1001 at 2:00 pm Charging and Transport in Amorphous Dielectrics and Reliability Implications for RF-MEMS Friday, February 1st Michael Zeitchek Thesis Defense Birck 2001 at 9:00 am Paul West Preliminary Exam Birck room 1001 at 9:30 am Novel Techniques for Quasi Three-Dimensional nanofabrication of Transformation Optics Devices OSA-Purdue Chapter Meeting Birck room 1001 at 11:00 am Thank you, Heather Anthrop Birck Nanotechnology Center Purdue University 1205 West State Street West Lafayette, IN 47907 (765) 494-7053

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Talk by Krishna Jayant (Cornell University) - "Interfacing Cells and Biomolecules with Floating Gate Ion Sensitive Transistors"
by Sambit Palit 22 Jan '13

22 Jan '13

This is an invitation for a talk by Krishna Jayant, graduate student from Cornell University. Title: Interfacing Cells and Biomolecules with Floating Gate Ion Sensitive Transistors Date/Time: Jan 25th (Friday), 4:30PM Location: Birck 2001.

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Reminder: Prof. Roger Howe Seminar - today at 11am in BRK 1001
by Turner, Jaime J 22 Jan '13

22 Jan '13

[cid:image001.png@01CDF887.E4289270] Jaime Turner Birck Nanotechnology Center Purdue University 1205 West State STreet West Lafayette, IN 47907-2057 (765) 494-3509 jjturner(a)purdue.edu

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FW: All User Meeting make-up session
by Reger, Ronald K 22 Jan '13

22 Jan '13

Message from Steve Jurss: From: Jurss, Stephen E Sent: Tuesday, January 22, 2013 8:58 AM To: Reger, Ronald K Subject: All User Meeting make-up session Users, This is the last All User training session: MRGN 121 at 3:00pm-4:00pm today. Please remember to bring your Birck ID. Stephen Stephen E. Jurss CIH, CSP Safety Manager Birck Nanotechnology Center 1205 W. State Street West Lafayette, IN 47907 Tx: 765-496-8337 E-mail: sejurss(a)purdue.edu<mailto:sejurss@purdue.edu>

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BNC e-news
by Anthrop, Heather L 18 Jan '13

18 Jan '13

Monday, January 21st Martin Luther King Jr. Day University Closed http://www.purdue.edu/newsroom/releases/2013/Q1/several-purdue-events-plann… Tuesday, January 22nd XPS Lite Workshop Introduction to CasaXPS Birck Room 2001 at 9:00 am http://www.purdue.edu/discoverypark/nanotechnology/events/view.php?id=1182 Roger Howe Seminar Vacuum Nano systems for Energy Conversion Birck room 1001 at 11:00 am http://www.purdue.edu/discoverypark/nanotechnology/events/view.php?id=1189 All User Meeting Make-up Session MRGN 121 at 3:00 pm You must have your Birck ID with you to confirm attendance. **If you have not attended a previous session and do not attend this one your Birck access will be revoked** Wednesday, January 23rd XPS Lite Workshop Introduction to CasaXPS Birck Room 2001 at 9:00 am http://www.purdue.edu/discoverypark/nanotechnology/events/view.php?id=1182 Thursday, January 24th Solar Seminar Series Bryan W. Boudouris Design of Optoelectronically-active Polymers for Organic Photovoltaic Applications Birck room 2001 at 3:30 pm http://www.purdue.edu/discoverypark/nanotechnology/events/view.php?id=1222 Friday, January 25th OSA-Purdue Chapter Birck room 1001 at 11:00 am New members always welcome Thank you, Heather Anthrop Birck Nanotechnology Center Purdue University 1205 West State Street West Lafayette, IN 47907 (765) 494-7053

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FW: All User Meeting Make-up Session
by Reger, Ronald K 18 Jan '13

18 Jan '13

Message from Steve Jurss: From: Jurss, Stephen E Sent: Friday, January 18, 2013 10:12 AM To: Reger, Ronald K Subject: All User Meeting Make-up Session Users, When: January 22nd from 3:00pm-4:00pm Where: MRGN 121 Please have your Birck ID with you. You will need to swipe it at the door as proof of attendance. Stephen Stephen E. Jurss CIH, CSP Safety Manager Birck Nanotechnology Center 1205 W. State Street West Lafayette, IN 47907 Tx: 765-496-8337 E-mail: sejurss(a)purdue.edu<mailto:sejurss@purdue.edu>

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FW: All User Meeting Tonight
by Reger, Ronald K 17 Jan '13

17 Jan '13

Message from Steve Jurss: From: mailman-bounces(a)ecn.purdue.edu [mailto:mailman-bounces@ecn.purdue.edu] On Behalf Of Jurss, Stephen E Sent: Thursday, January 17, 2013 2:55 PM To: 'bnc-facility-notice-owner(a)ecn.purdue.edu' Subject: All User Meeting Tonight Users, When: January 17th from 7:00pm-8:00pm Where: Lily Hall 1-105 You will only need to attend one session. If you do not your card access to the facility will be suspended. Please have your Birck ID with you. You will need to swipe it at the door as proof of attendance. Stephen Stephen E. Jurss CIH, CSP Safety Manager Birck Nanotechnology Center 1205 W. State Street West Lafayette, IN 47907 Tx: 765-496-8337 E-mail: sejurss(a)purdue.edu<mailto:sejurss@purdue.edu>

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