Next generation chalcogenide glasses for visible and IR ... · PDF fileNext generation...
Transcript of Next generation chalcogenide glasses for visible and IR ... · PDF fileNext generation...
Next generation chalcogenide glasses
for visible and IR imaging
Dan Hewak, Andrea Ravagli and John Lincoln
Novel Glass Group Optoelectronics Research Centre University of Southampton Southampton, UK, SO17 1BJ [email protected] SPIE Security + Defence and Remote Sensing 2016 Edinburgh International Conference Centre (EICC) September 28th, 2016
With particular thanks to:
Kevin Huang CVD and 2D
and Ghadah Alzaidy, Solar Cells
Armen Aghajani Glass Characterization
Chris Craig Technical Support
Katrina Morgan Optoelectronic Devices
Paul Bastock Optical Fibre
Ed Weatherby Laboratory Infrastructure
Andrea Ravagli New Material Development
Nicos A 2D Materials and Devices
Ioannis Zeimpekis 2D and plasmonic devices
Why More Glass? “… In photonics, you never have the
material you want!”
Outline
• Chalcogenide Glass - Introduction
• Glass Manufacture – Improved Compositions
• Thermal, Optical, Mechanical Properties
• Validating and Practical Applications
What is a Chalco-gen-ide?
– From Greek Ore-formed
– Chalcogen is derived from the Greek words Halkos and Genes. Halkos is copper but it is used here in the more poetic sense of ore and genes implies something that is produced or formed.
– The suffix –ide indicates the combination of the chalcogen with a more electropositive element.
Typical Amorphous Compositions
– As-S, As-S-Se, Ge-Sb-Te
– Commercially available glasses are toxic!
– Seen in various forms: crystalline, single crystal, quantum dots, phosphors, ceramics
Early ORC Research Focussed On
– Gallium Lanthanum Sulphides
– Germanium Sulphides
– With Many Other Explored
What is Chalcogenide Glass?
Why are they Interesting?
Conduct electricity
Switch between
crystal states
Transparent in
infrared
Cut, polished, extruded,
made into fibre and thin
film
Commercially
important
2D materials
Sensitive to
light
Stable to 600°C
Easily doped with RE
ions
Supply Chain Long Established
Commercially Available Compositions
A New Family of Chalcogenides
Ga:La:S and Modifiers
Chalcogenide Glass Manufacture
• Ball Mill / Hot Press
• Sealed Ampoule Techniques
• Conventional Melt Quenching
• Chemical Vapour Deposition (CVD)
Ga:La:S Melt Quenching
• Raw Materials batched in nitrogen purged glove box
• Sulphides melted in vitreous carbon crucibles
• Typically 24 hours at 1150oC in flowing argon
• Quenched to below glass transition temperature
• Annealed at 500oC, depending on ingot size
Glovebox
Furnace Enclosure
Gas Purification
Gas Inlet
Focus on Glass Melt Facility
System Capability:
• Designed completely in-house so
flexible
• Instrumented to guarantee consistency
• National Instrument and Labview code,
provide recipes and automation.
• MFC flow controls
• Online dew point measurement
• State of the art purifiers include 3nm
particulate filters and up to 100 ppt
removal in certain gases.
• Gas detection and automated shutoff
• UPS power backup for 8 hours
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
PP
M (
v)
Argon line – Conversion Rig
0
0.05
0.1
0.15
0.2
PP
M (
v)
H2S line Nitrogen Purge
Daily Monitoring of Gas Purity
Sample: LD1592
Current Glass Purity
Why more Materials Research?
“… In photonics, you never have the
material you want!”
FIG
. 1
0A
Increasing Se content shifts IR edge, maintaining visible transmission
Ga-La-S
Ga-La-S-Se
Increasing Se
Compositional Modifications Improving IR Transmission
Optical Properties (in progress)
Trade Name
AMTIR-6
GASIR-1
VITRON IG4
Ga-La-S
Ga-La-S-Se
Composition
As40S60 Ge22As20Se58 Ge10As40Se50 Ga13La7S40 Ga28La12S36Se24
Transmission window 0.65-12 µm 1-16 µm 1-12 µm 0.55-8µm
0.65 – 12 µm
Index at 5 mm 2.41 2.51 2.62 2.27
Temperature dependence dn/dT
(10-6/oC )
55 @10.6μm
19.9 @10.6μm
Zero Dispersion (µm) 5.5 4
Dispersion @ 20oC 198@4μm
Ga-La-S
AMTIR-6
GASIR-1
2.2
2.3
2.4
2.5
2.6
2.7
2 4 6 8 10
Re
fra
ctive
in
de
x
Wavelength (microns)
IG4
AMTIR-6
GASIR
GLS
ZnSe
Visible to mid-IR Transmission
Thermal 7.5-14mm
Off-shelf twin
camera thermal
imaging
Through GLS
Loss of long
wavelengths
Image
deteriorates
Thermal
blocked
Through GLS-Se
Long
wavelength
transmitted
Visible and IR
transmission
Visible and LWIR Imaging with Modified GLS
Thermal 7.5-14mm
Visible
Hybrid
IG4
Thermal Properties
Viton
Trade Name
AMTIR-6
GASIR-1
VITRON IG4
Ga-La-S
Ga-La-S-Se
Zn-Se
Composition
As40S60 Ge22As20Se58 Ge10As40Se50 Ga13La7S40
Ga28La12S36Se
24
Glass Transition Tg (oC)
180 292 225 580 500
Softening Point (oC)
208 310 600 563
Onset of Melting Tm (oC)
310 830 773 1525
Coefficient of Thermal Expansion
(x10-6 oC-1) 21.4 17 20.4 9.2 10.6 7.6
Specific Heat Capacity (J/gK)
0.109 0.36 0.37 0.54 0.339
Thermal Conductivity
(W/mK) 0.17 0.28 0.18 0.43 18
Differential Thermal Analysis and Weight Loss
Perkin Elmer Diamond Tg/DTA
Mechanical Properties
Viton
Trade Name
AMTIR-6
GASIR-1
VITRON IG4
Ga-La-S
ZnSe
Composition As40S60 Ge22As20Se58 Ge10As40Se50 Ga13La7S40 ZnSe
Density (g/cm3) 3.2 4.4 4.47 4.04 5.27
Poisson’s Ratio 0.24 0.28 0.24 0.28
Young’s Modulus (GPa) 15.9 17.89 20.5 59 67.2
Knoop Hardness (200g indenter)
(kg/mm2) 109 114 206 105-120
Corrosion Resistance
• Chemical vulnerability weakness for previous chalcogenides
– IG4 (Ge:As:Se) 4 day 23% mass loss in Ethylene-diamine
Control
• GLS surface after 1 month exposure to
– Cleaning Agents
– Amine Solvents
• Significantly improved chemical resistance
Control Acetone IPA Methanol
20
X im
age surface
Control Propylamine Butylamine EDA
Diamond Cut Trials
20
Property II-VI Incorporated
SN:001
• 9 A rms roughness measured near the
diameter of the part
Glass Optimization
10:90 50:50 90:10
(The Hard Way!)
High Throughput Material Discovery Brian Hayden
Glass Optimization (The Efficient Way!)
Paul Bastock, Chris Craig
ChAMP Program
Fabrication •Bulk Glass
• Fibre
•Thin film
• Laser processing
Demonstration •Electronic Devices
•Photonic Devices
•Non Linear Devices
•New Feasibility projects
Optimisation •High throughput
screening
•Ab-initio modelling
ChAMP – Chalcogenide Advanced Manufacturing Partnership
(2015 - 2020)
Our University Partners will ensure the
materials we develop will be used in
cutting edge, emerging research
with flexibility to move
to new emerging areas
and resourcefulness to adapt to new
industrial requirements.
Summary
• Chalcogenide glass and a focus on manufacturing has
accelerated research and collaborations
• Compositional modifications have allowed a new family of glasses with improvements in several key characteristics
• Now further characterizing and developing these materials
• Open for collaboration
•http://chalcogenides.net
ChAMP – Chalcogenide Advanced Manufacturing Partnership
(2015 - 2020)
Acknowledgements
The support of the UK’s Engineering and Physical Science Research Centre is gratefully acknowledged, through:
EP/J00278X/1 FLITES : Fibre-Laser Imaging of gas Turbine Exhaust Species (ORC) EP/I019065/1 Chalcogenide optoelectronic platform for next-generation optoelectronics EP/H02607X/1 EPSRC Centre for Innovative Manufacturing in Photonics EP/G060363/1 ChAMP – Chalcogenide Advanced Manufacturing Partnership
More details at http://chalcogenides.net