Gredig Research Lab:Gas Sensors, Solar Cells,
Low-Dimensional Magnetism
Thomas GredigDepartment of Physics & AstronomyCalifornia State University, Long Beach
Bite of Science, February 22, 2016
Outline
n Career of a Physicistn Research at CSULB
¨Gas Sensors¨Solar Cells¨Magnetism
n Applications (Energy-Related)¨Energy Absorption (Cans)¨Energy Conversion (Solar Cells)¨Energy Storage (Aluminum Foil)
n Outreach: PhysTEC, Society of Physics Students
Typical Career Road Map
Professor
Post-doc
Ph.D.
B.S.
A Quarter Century
n B.S. Physics (~ 4 years)n M.S. Physics (~ 2 years)n Ph.D. Physics (~ 3 years)n Post-doctoral positions (3 – 5 years)n Assistant Professor (5 – 6 years)n Associate Professor (4 – 5 years)n Professor
CSU Long Beach – Gredig Group
Open Questions
n Gas Sensors¨Monitor gas leakage¨Measure emissions in industry¨Detect explosives, biological warfare agents
n How to distinguish different molecules?n What materials are suitable?
Organic Material: Phthalocyanine
H
C
N
FePhthalocyanine MoleculeImage: T. Gredig
me.
me.met
hano
l
met
hano
l
me.
200 400 600
0.8
1.0 n
orm
aliz
ed c
urre
nt
Time (min)
small grains (25 C) large grains (200 C)
Transport Measurement in CoPc
• sensitivity to analyte (reversible)• more drift for higher growth temperature
dosage
Optimized Sensor
n Patent: U.S. 8,384,409:¨Ultra-thin Organic TFT Chemical Sensor
n Applied Physics Letters, 90, 263506 (2007).
Zinc Phthalocyanine – based Solar Cell
17
Open Questions: What material? What structure (smooth, rough)?
M.S. Thesis of Eric Muckley, now at Oak Ridge Laboratories
Finished Solar Cell
18 Image: Eric Muckley, CSU Long Beach
Challenges in Magnetism Today (Applications)
n Stronger magnets (work = force * distance)n Lighter magnets (mass)n Transparent magnetsn Optically active magnetsn Flexible (non-brittle) magnets
Strongest Magnets
Neodymium Iron Boron Magnets
http://www.magnetnrg.com/pm-history.html
Thermal Gradient Purification
Vacuum Deposition System
Thermal Evaporation (Sublimation)
Typical Samples: 10 x 4 mm2
Magnetic Relaxation in 1D
Gredig et al., Phys. Rev. B (2017).
General Approach to Research
n Preparation: Sample / System
n Model / Simulation
n Experiment
n Comparison with Prediction
n Use Model, refine, new Predictions
General Approach to Research
n Preparation: Sample / System¨Build a Capacitor (Al foil, …)
n Model / Simulation¨PhET simulations (phet.colorado.edu)
n Experiment ¨Arduino microcontroller
n Comparison with Prediction¨R, GnuPlot, Python
n Use Model, refine, new Predictions
Heating and Cooling of Black/Silver Can
Black
Silver
Applications: Energy Conversion
n Solar Cells: ~ $5n What is the dependence on angle?n What is the shape of the I-V curve?n How does light color, temperature, area, light
intensity affect the solar cell performance?
PhET Simulation: Circuit Construction Kit
n Phet.Colorado.edu
Need Ideas?
n American Association of Physics Teachers¨K-12 Teacher Portal
n American Journal of Physics¨Read¨Publish
n AAPT ComPADRE¨Resource Library
Outreach
n High School Teacher in Residencen PHYS 390 - Exploring Physics Teaching
¨Visits to H.S.n PhysTEC at CSULB
¨HS teachers share experiments on Thursdays on Demo Day
¨Newsletter¨ https://web.csulb.edu/colleges/cnsm/sas/phystec/¨Questions, email: [email protected] or
call (562) 985-7026
PhysTEC
Society of Physics Students (SPS)n CSU Long Beach SPS visited High Schools with Physics Demos