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 dh@orc.soton.ac.uk 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