synthesis and characterization of rare earth nanomaterials and their biological and photonic...
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Synthesis and Synthesis and Characterization of Rare Characterization of Rare Earth Nanomaterials and their Biological Earth Nanomaterials and their Biological
and Photonic Applicationsand Photonic Applications
Dhiraj SardarDhiraj SardarDepartment of PhysicsDepartment of Physics
University of Texas at San AntonioUniversity of Texas at San AntonioMarch 10 and 11, 2011March 10 and 11, 2011
NORTHWESTERN UNIVERSITY
NSF - PREM - MRSEC
Outline
• Introduction to Rare Earths• Methods • Important Facilities • Results – Theoretical and Experimental• Potential Applications• UTSA Physics Department -PREM• PREM Students• PREM Publications and Acknowledgements
Introduction to Rare Earths
Electronic Configuration (RE3+) : Incomplete inner 4fN orbital : [Xe]4fN5s25p6(N=113)
Optical Properties : Strong absorption and fluorescence : Wide range of excitation and emission (UV-VIS-IR)
Applications : Lasers, Display, Sensor, Therapy, Biomedical imaging, etc.
Energy levels of trivalent rare earths (RE3+ )
Electron charge distribution in different orbitals for RE ions showing the shielding of 4f electrons by outer 5s and 5p electrons
Methods
1. Synthesis• Solvothermal/Hydrothermal• Precipitation• Thermolysis
2. Morphology Characterization • XRD, EDX • SEM, TEM, STEM• AFM
3. Optical Characterization• Refractive Index• Optical Absorption/Reflection/Scattering• Steady State Emission• Fluorescence Lifetime• Optical Gain• Efficiency(Internal, External, Conversion, Slope)• FTIR/Raman
Important Facilities
Laser Research Laboratory Lasers: Argon, Nd:YAG,
Ti:Sapphire, Diode (Vis-IR) Cary-14 Spectrophotometer SPEX 1250M Monochromator Cryogenic Cryostat
Microscopy Laboratory STEM w/EDX HR-TEM w/EDX AFM Raman
XRD
JEOL-ARM200F(0.06 nm resolution)JEOL-ARM200F(0.06 nm resolution)
RESULTS
STEM imaging of the Nd3+ distribution
Nd3+:Sc2O3
Blue = Scandium , Red = OxygenBlue = Scandium , Red = Oxygen
Theoretical (Judd-Ofelt Formalism)
4 2 22
32,4,6
64 ( 1)( ) | |
3 (2 1) 9t
rad tt
e n nA J J J U J
h J
(Judd-Ofelt Model)
Radiative Quantum Efficiency:
fl rad
rad rad nr
A
A A
Arad=radiative decay rateAnr=nonradiative decay rate
1( )
nr mp ET OH imp
fl rad nr
A A A A A
A A
Radiative Process:
Major Nonradiative Processes:
1.Multiphonon relaxation (Amp)2.Energy transfer between ions (AET)3.Hydroxyl content/High frequency vibrational groups (AOH)4.Impurity (Aimp)
4I9/2
4I11/2
4I13/2
4I15/2
980nmPump
Amp
AOH
AET
AET1550nm550nm
650nm
4S3/2
4F7/2
4F9/2
Er3+
J
J
( )radA J J
Wavelength (nm)
500 600 700 800
Abs
orpt
ion
Coe
ffici
ent (
cm-1
)
0
10
20
30
40
2H(2)9/2 + 4F5/24F3/2 + 4S3/2
4F9/2
4G11/2+2K15/2 +
2G(1)9/2+2D(1)3/2
4G7/2 +2K13/2 + 4G9/2
4G5/2 +1G(1)7/2+
2H(2)11/2
Wavelength (nm)
500 600 700 800
Abs
orpt
ion
Coe
ffici
ent (
cm-1
)
0
5
10
15
20
25
30
4G7/2 +2K13/2 + 4G9/2
4G5/2 +1G(1)7/2+
2H(2)11/2
4F9/2
4F7/2 +4S3/2
2H(2)9/2 +4F5/2
4G11/2+2K15/2 +
2G(1)9/2+2D(1)3/2
Nd3+:Y2O3 in HEMA
Nd3+:Y2O3 Ceramic
Polymer embedded samples yield similar spectral features to polycrystalline ceramic sample
Wavelength (nm)
500 600 700 800
Abs
orpt
ion
Coe
ffici
ent (
cm-1
)
0
5
10
15
20
25
30
35
4G11/2+2K15/2 +
2G(1)9/2+2D(1)3/2
4G7/2 +2K13/2 + 4G9/2
4G5/2 +1G(1)7/2+
2H(2)11/2
4F9/2
4F7/2 +4S3/2
2H(2)9/2 +4F5/2
Nd3+:Y2O3 in Epoxy
Nd3+:Y2O3 Absorptions from Ceramic and Embedded in Polymers
RE3+:Y2O3 Emissions from Nanoparticles
Wavelength (nm)
580 600 620 640 660 680 700 720
Flu
ores
cenc
e In
tens
ity (
Arb
. Uni
ts)
0.0
0.2
0.4
0.6
0.8
1.0
1.2
5 D0
7 F
0
5 D0
7 F
1
5 D0
7 F 2
5 D0
7 F
3
5 D0
7 F
4
Nanoparticles Epoxy embedded
Eu3+:Y2O3
Nd3+:Y2O3
Comparative Results of Nd3+ in polymer, ceramic, and single crystals
Parameter HEMAa Epoxyb Ceramicc Ceramicd Crystale Crystalf
2(10-20cm2) 6.75 10.97 10.52 4.09 8.55 4.08
4(10-20cm2) 8.47 5.68 5.06 2.97 5.25 5.53
6(10-20cm2) 3.65 5.37 5.28 3.85 2.85 3.97
rad (ms) 0.623 0.549 0.532 0.354 0.655 0.589
fl (ms) 0.584 0.499 0.504 0.318 - -
*Q(%) 93.7 90.9 94.7 89.0 - -*Internal radiative quantum efficiencya,b,c Sardar et al., Polymer Internationa (2005), J. Appl Phys. (2004, 2005)d Kumar et al., IEEE J Quant. Elect.(2006)E Kaminskii, Laser Crystals, (1996)f Morrison et al., J.Chem. Phys (1983)
Other RE-Doped Materials and their Potential Applications
Transparent Nd:YAGCeramic
Eu:Y2O3 :HEMA Polymer
Yb,Er :Phosphate GlassInset:Pr :Phosphate Glass
Nd:YAG Single Crystal
Up and Down Conversion (Imaging, Display, Therapy, Sensing, Security, Lighting, etc.)
Eu:Y2O3 nanoparticles(Homogeneous precipitation)Host: La2O2S
Top: 980 nm Ex (10mW)Bottom: 320 nm Ex:
YbEr YbEr YbEr
YbTm SrS:EuDy
Eu Tb Eu2+
What is so Unique about RE (NdWhat is so Unique about RE (Nd3+3+) for Biomedical ) for Biomedical Applications?Applications?
Large Stoke’s shift (~500nm)& strong emission
Multi-frequency absorption & emission
Long fluorescence lifetimes Optical properties
“independent” of size Nontoxic
Wavelength (nm)
500 600 700 1000 1100
Inte
nsity
0.0
0.2
0.4
0.6
0.8
1.0
1.2absorption emission
Imaging Application of RE Nanoparticles
Present technology: Organic Dyes and Quantum DotsAdvantages-Highly FluorescentDisadvantages-UV excitation causes autofluorescence, reducing S/N ratio -Size tunability is needed for quantum dots for proper excitation -Toxicity of the composition, Photobleaching
Color tunable Q dots
Autofluorescence After background subtraction
Future technology: Rare Earth-doped Nanoparticles Advantages-Highly Fluorescent, wide range of excitation and emission (UV-IR), no autofluorescence, nontoxic, no size requirement, no photobleaching
Confocal image of the 980 nm excited Emissions (550 and 670 nm) from
Yb,Er:CaF2 Nanoparticles
a b
(a) Live cell (mouse fibroblast) image with green upconversion under 980 nm Exc.
(b) Cell autofluorescence under UV Exc.
Photodynamic Therapy with IR Upconversion(IPDT)
Advantages: IR Upcoversion, 5 times penetration depth compared to Current UV-X PDT
• Advanced Engineering and Technology (AET) Building ($82.5M; December 2009)
– Physics Department occupies the 3rd floor (over 14,000 sq. ft. of lab space)
– $11.2M spent by UTSA to Renovate Physics Research Laboratories
• Thin Films Laboratory (AET)– ALD, Laser Deposition
• Biophotonics Research and Imaging Laboratory (AET)
• Synthesis Labs (AET)– Nanomaterials– Nanophotonics and Laser Materials
• Terahertz Laboratory (AET)• Computational Physics Laboratories (AET)
– Access to the Texas Advanced Computing Center (TACC at UT Austin)
• Advanced Microscopy Laboratory (Science Building)
– TEM-STEM, SEM, AFM, Raman– Including the most advanced spherical
aberration corrected STEM (JEOL ARM 200F)
UTSA Physics Department- PREMUTSA Physics Department- PREM
Tenure-track facultyTotal: 13; PREM: 76 Minority; 3 Women2 Hispanic Women 1 African American Woman
UTSA PREM ResearchersUTSA PREM Researchers
• Dr. Jianhui Yang (2010)
• Dr. Ajith Kumar (2011)
• Erik Enrique
• Joseph Barrios
• Edward Khachatryan
• Robert C. Dennis
• Brian Yust
• Leland Page
• Kenneth Ramsey
• Madhab Pokrhel
• Nathan Ray
• Francisco Pedraza
• Devraj Sandhu
• Jesse Salas
• Hector Barron-Escobar
• Marcus Najera
• Gilberto Cassilas Garcia
• Zurab Kereselidze
Published or in Press:• Chandra, S.*, Francis Leonard Deepak, J. B. Gruber, and D. K. Sardar, “Synthesis, Morphology, and Optical Characterization of Er3+:Y2O3”, J. Chem.
Physics C, 114, 874-880 (2010). • Burdick, G. W., J. B. Gruber, K. L. Nash, and D. K. Sardar, “Analyses of 4f11 Energy Levels and Transition Intensities Between Stark Levels of Er3+ in
Y3Al5O12”, Spectroscopy Letters: 43, 406-422 (2010). • Gruber, J. B., G. W. Burdick, S. Chandra*, and D. K. Sardar, “Analyses of the Ultraviolet Spectra of Er3+ in Er2O3 and Er3+ in Y2O3”, J. Appl. Phys., 108,
023109: 1-7 (2010).• Chandra, S.*, J. B. Gruber, G. W. Burdick, and D. K. Sardar, “Material Fabrication and Crystal-Field Analysis of the Energy Levels in Er3+ doped Er2O3
and Y2O3 Nanoparticles Suspended in Polymethyl Methacrylate”, J. Appl. Pol. Sci. (in Press) (2011).• Yang, J. and D. K. Sardar, “One-Pot Synthesis of Coral-Shaped Gold Nanostructures for Surface-Enhanced Raman Scattering”, J. Nano Res. (in Press)
(2011).• Yang, J., R. C. Dennis*, and D. K. Sardar, “Room-Temperature Synthesis of Flowerlike Ag Nanostructures Consisting of Single Ag Nanoplates”, Mater.
Res. Bull. (in Press) (2010).• B. Yust*, D. K. Sardar, and A. T. Tsin, "Phase conjugating nanomirrors: utilizing optical phase conjugation for imaging", SPIE Proceedings, Vol. 7908 (In
Press) (2011).
• Francis Leonard Deepak, Rodrigo Esparza, Belsay Borges, X. Lopez-Lozano, Miguel Jose Yacaman, Rippled and Helical MoS2 Nanowire catalysts – An aberration corrected STEM study. Catalysis Letters, In Press, 2011.
• Page, L*, Maswadi, S, Glickman, RD, “Optoacoustic Spectroscopic Imaging of Radiolucent Foreign Bodies”, in Medical Imaging 2010: Ultrasonic Imaging, Tomography, and Therapy, D'hooge, J; McAleavey, SA, Eds., Proc. SPIE, Vol. 7629, pp 7629OE-1 – 7629OE-7, 2010.
• Maswadi*, S, Glickman, RD, Elliott, WR, Barsalou N,. “Nano-Lisa for In Vitro Diagnostic Applications”, in Photons Plus Ultrasound: Imaging and Sensing 2011, Oraevsky AA, Wang LV, Eds, Proc. SPIE, Vol. 7899, in Press, 2011.
• Page, L*, Maswadi, S, Glickman, RD, “Identification of Radiolucent Foreign Bodies in Tissue Using Optoacoustic Spectroscopic Imaging”, in Photons Plus Ultrasound: Imaging and Sensing 2011, Oraevsky AA, Wang LV, Eds., Proc. SPIE, Vol. 7899, in Press, 2011.
• Francis Leonard Deepak, G. Casillas-Garcia*, H. Barron*, R. Esparza and M. Jose-Yacaman, New Insights into the structure of Pd-Au nanoparticles as revealed by aberration-corrected STEM”, in Press, 2011
• V. H. Romero, W. Egido, Z. Kereselidze*, C. M. Valdez, .E. Michaelides, X. G. Peralta, M. Jose-Yacaman, F. Santamaria. Neurons preferentially internalize goldnanostars with strong and precise photothermal properties. Submitted to Nanomedicine NBM, 2011.
• X. G. Peralta, “Plasmon modes for terahertz detection: Terahertz Plasmon modes in grating coupled double quantum well field effect transistors”, released by LAP Lambert Academic Publishing (2010-08-30) - ISBN-13 : 978-3-8383-9371-1 (2010).
• Wilmink, G. J., Rivest, B. D., Roth, C. C., Ibey, B. L., Payne, J. A., Cundin, L. X., Grundt, J. E., Peralta, X., Mixon, D. G. and Roach, W. P. , “In vitro investigation of the biological effects associated with human dermal fibroblasts exposed to 2.52 THz radiation”. Lasers in Surgery and Medicine, n/a. doi: 10.1002/lsm.20960, 2011.
• J. Antunez-Garcia, S. Mejia-Rosales, E. Perez-Tijerina, J. M. Montejano-Carrizales and M. Jose –Yacaman. “Coallescence and collision of gold nanoparticles”. Materials, 4: 368-379, doi:10.3390/ma4020368, 2011.
16 Published, 4 other papers submitted, and 11 more under preparation
All Publications Acknowledge NSF-PREM Support: Grant No. DMR-0934218
PREM Publications PREM Publications (2010-11)(2010-11)
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