1st year ppt-1.ppt...a"marie"skłodowska/curie"ini4al"...
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A"Marie"Skłodowska/Curie"Ini4al"
Training"Network"Postgraduate+Research+on+Dilute+Metamorphic+Nanostructures+and+Metamaterials+in+Semiconductor+Photonics++
Laser&wri)ng&on&nanoscale/LEDs&
based&on&dilute&nitrides.&
Mayank&Sharma&
PhD&Student&
“La&Sapienza”&University&of&Rome.&
&
Supervisors:&Prof.Antonio&Polimeni&&&Dr.Marco&Felici&
A"Marie"Skłodowska/Curie"Ini4al"
Training"Network"Postgraduate+Research+on+Dilute+Metamorphic+Nanostructures+and+Metamaterials+in+Semiconductor+Photonics++
Background+of+project+• Pho ton i c s& i s& impo r t an t& f o r&
informa)on& and& communica)on&
technologies& (ICT).& Eg.,& fiber& op)cs,&
internet.&
• In&ICT,&photon&sources&are&needed&to&
be&operated&at&1.31μm&and&1.55μm.&
• U l =m a t e+ g o a l + i s + p r o d u c e+reproducible+ nano?structuring+techniques,+ and+ fabrica=on+ of+nanoscale+LEDs+using+them.&
• Fabrica)on& of& nanoscale/LEDs& based&
on& laser/annealing& of& hydrogen&
irradiated&(InGa)(AsN)&will&allow&us&to&
move&forward&in&this&field.&
A"Marie"Skłodowska/Curie"Ini4al"
Training"Network"Postgraduate+Research+on+Dilute+Metamorphic+Nanostructures+and+Metamaterials+in+Semiconductor+Photonics++
Objec=ves+• Op)mize&condi)ons&for&complete&N?passiva=on&in&the&InGaAsN&Quantum&Well&
(QW)&using&hydrogena)on&technique.&
• To&create&site/controlled&nanoscale&light&emi[ng&spots&or&ordered&LED+arrays+by+laser+wri=ng&using&InGaAsN&structures.&
&
• Materials&development&will&be&targeted&to&key&wavelengths&in&ICT,&i.e.&1.31+μm+and+1.55+μm.+
A"Marie"Skłodowska/Curie"Ini4al"
Training"Network"Postgraduate+Research+on+Dilute+Metamorphic+Nanostructures+and+Metamaterials+in+Semiconductor+Photonics++
Single+Photon+Sources+• Bo]om&row&corresponds&to&semiconductor&based&sources&that&can&be&integrated&
in&optoelectronic&devices.+
A"Marie"Skłodowska/Curie"Ini4al"
Training"Network"Postgraduate+Research+on+Dilute+Metamorphic+Nanostructures+and+Metamaterials+in+Semiconductor+Photonics++
QD apps
No&need&of&
posi)on&control&
of&single&QDs!&
Photovoltaics&
Illumina)on&
Biomedical&
A"Marie"Skłodowska/Curie"Ini4al"
Training"Network"Postgraduate+Research+on+Dilute+Metamorphic+Nanostructures+and+Metamaterials+in+Semiconductor+Photonics++
Precise&control&of&QD&&
posi)on&and&spectral&emission&
is&needed&for&advanced&applica)ons!&
A"Marie"Skłodowska/Curie"Ini4al"
Training"Network"Postgraduate+Research+on+Dilute+Metamorphic+Nanostructures+and+Metamaterials+in+Semiconductor+Photonics++
QD&Diffrac)on&limit&&
>>&typical&dot&dimension&
Solu)on:&Exploit&Near&field!&
Laser+annealing+
Laser&annealing&
using&objec)ve&
Laser&annealing&
using&SNOM&
A"Marie"Skłodowska/Curie"Ini4al"
Training"Network"Postgraduate+Research+on+Dilute+Metamorphic+Nanostructures+and+Metamaterials+in+Semiconductor+Photonics++
GaAs
GaAs
GaAsN QW
Laser&wri)ng& can& be& used& to& dissociate& the&N/H& complex& thus& red/shiding&
the&QW&emission&towards&the&peak&energy&(~1.3&eV)&of&the&QW&PL&band&in&
the&as/grown&sample&(i.e.&without&H).&
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Intensity (
counts)
5 µm
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Intensit
y (coun
ts)
4 µm
2 µm
before & after laser exposure
Band&gap&modula)on&by&laser&wri)ng&
Focused Laser beam
GaAsN hydrogenated GaAsN
1.3 1.4 1.5
GaAs
QW
Before Hydrogenation
After Hydrogenation
T = 300 K
PL
Inte
nsity
(a.
u)
Energy (eV)
GaAs
A"Marie"Skłodowska/Curie"Ini4al"
Training"Network"Postgraduate+Research+on+Dilute+Metamorphic+Nanostructures+and+Metamaterials+in+Semiconductor+Photonics++
Summarizing+&
&
Inser)ng&hydrogen&(by&ion/beam)&increases&the&gap&&
(towards&the&GaAs&value)&
&
&
Removing&hydrogen&(by&light)&decreases&the&gap&
(towards&the&GaAsN&value)&
A"Marie"Skłodowska/Curie"Ini4al"
Training"Network"Postgraduate+Research+on+Dilute+Metamorphic+Nanostructures+and+Metamaterials+in+Semiconductor+Photonics++
Results+of+laser+annealing+• Quantum&confinement&has&been&achieved&by&this&technique.&We&can&make&
quantum&dots&on&specific&loca)ons.&+
PL Imaging
A"Marie"Skłodowska/Curie"Ini4al"
Training"Network"Postgraduate+Research+on+Dilute+Metamorphic+Nanostructures+and+Metamaterials+in+Semiconductor+Photonics++
Experimental&techniques&used&so&far&
A"Marie"Skłodowska/Curie"Ini4al"
Training"Network"Postgraduate+Research+on+Dilute+Metamorphic+Nanostructures+and+Metamaterials+in+Semiconductor+Photonics++
Experimental+techniques+• Hydrogena)on&to&
achieve&full&N&
passiva)on.&
• Macro&&µ&
photo/luminescence&
measurements&
• Data&plo[ng&&&
Analysis&
QWs+
A"Marie"Skłodowska/Curie"Ini4al"
Training"Network"Postgraduate+Research+on+Dilute+Metamorphic+Nanostructures+and+Metamaterials+in+Semiconductor+Photonics++
Results&&&Analysis&
A"Marie"Skłodowska/Curie"Ini4al"
Training"Network"Postgraduate+Research+on+Dilute+Metamorphic+Nanostructures+and+Metamaterials+in+Semiconductor+Photonics++
//&Untreated&–&Black&
//&Hydrogenated&(2B=2*1017&ions/cm2)&//&Red&&
x+1.75+
Annealed InGaAsN/GaAs QW
Non-annealed InGaAsN/GaAs QW
Effect+of+thermal+annealing+
//&Untreated&–&Black&
//&Hydrogenated&(1C=1*1018&ions/cm2)&–&Red&
//&Hydrogenated&(2C=2*1018&ions/cm2)&–&Blue&
x+2.14+ x+3.22+
0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5 -5000 0
5000 10000 15000 20000 25000 30000 35000
Inte
nsity
Energy (eV) 1.02 1.04 1.06 1.08 1.10 1.12 1.14
0 5000
10000 15000 20000 25000 30000 35000
Inte
nsity
Energy (eV)
• Hydrogena=on+usually+causes+a+blue?shiV+in+energy.+• But,&in&annealed&samples&(700+C+for+10+seconds),+the&effect&was¬&observed.&
Inte
nsity
(arb
.uni
ts)
Inte
nsity
(arb
.uni
ts)
A"Marie"Skłodowska/Curie"Ini4al"
Training"Network"Postgraduate+Research+on+Dilute+Metamorphic+Nanostructures+and+Metamaterials+in+Semiconductor+Photonics++
Hydrogena=on+of+different+set+of+samples+
A"Marie"Skłodowska/Curie"Ini4al"
Training"Network"Postgraduate+Research+on+Dilute+Metamorphic+Nanostructures+and+Metamaterials+in+Semiconductor+Photonics++
InAsN+vs.+GaAsN:+H+role+• Hydrogen&has&more&effect&on&GaAsN&w.r.t.&InAsN.&
InAsN/GaAs QW
1.00 1.20 1.40
PL In
tens
ity (a
rb. u
nits
)
Energy (eV)
GaAs1-x
Nx/GaAs QW
x=2.9% t = 6 nm
untreated
dH=5×1017 cm-2
dH=2.5×1019 cm-2
dH=5×1019 cm-2
GaAs
T = 10 K
P = 5 W⋅cm-2
GaAsN/GaAs QW
A"Marie"Skłodowska/Curie"Ini4al"
Training"Network"Postgraduate+Research+on+Dilute+Metamorphic+Nanostructures+and+Metamaterials+in+Semiconductor+Photonics++
What+happens+for+Intermediate+cases?+
A"Marie"Skłodowska/Curie"Ini4al"
Training"Network"Postgraduate+Research+on+Dilute+Metamorphic+Nanostructures+and+Metamaterials+in+Semiconductor+Photonics++
Laser+annealing+of+GaAsN+using+SNOM+
(a):%This%QD%is%fabricated%with%laser%power%of%1.1%mW%for%1%sec%
(b):%Measurements%from%QDs%fabricated%at%different%powers%with%exposure%@me%of%1%sec%
(b)
A"Marie"Skłodowska/Curie"Ini4al"
Training"Network"Postgraduate+Research+on+Dilute+Metamorphic+Nanostructures+and+Metamaterials+in+Semiconductor+Photonics++
Summary+• Blue/shid&in&thermally/annealed&sample&is&difficult&to&achieve&because&of&
forma)on&of&In/N&bonds.&
• In/N&bonds&causes&inhibi)on&of&hydrogen&effects.&
• The&reason&might&be&the&strain,&cohesive&energy,&etc.&which&inhibits&hydrogen&to&
passivate&nitrogen&in&indium&rich&samples.&
• Non?annealed+samples+have+shown+significant+blue?shiV+which&is&an&important&
step&in&my&project.&
• These&new&samples&are&also&emi[ng&at&room&temperatures&that&shows&that&they&
are&good&for&prac)cal&applica)ons.&
A"Marie"Skłodowska/Curie"Ini4al"
Training"Network"Postgraduate+Research+on+Dilute+Metamorphic+Nanostructures+and+Metamaterials+in+Semiconductor+Photonics++
Outputs–publica=ons,+talks,+posters,+outreach+• Talks:&
1. “Hydrogena4on" of" InGaAsN"QW"Samples”/&University& of& Cadiz:& 18th&May&
2016.&
2. “Effect" of" In/N" bonds" on" nitrogen" passiva4on" in" dilute" nitrile"semiconductors”/&University&of&Montpellier:&1st&September&2016&(France).&
3. “Laser" wri4ng" of" nanoscale" LEDs" based" on" dilute" nitrides”/+ Mid/term&
review&mee)ng&of&PROMIS&network,&London&(UK):&7th&December&2016.&
• Poster:&
1. “Indium" influence" on" the" hydrogen/induced" passiva4on" of" nitrogen" in"dilute" nitride" semiconductors”:% 19th& Interna)onal& Conference& on&Molecular& Beam& Epitaxy& (MBE& 2016):& 4/9& September& 2016,&
Montpellier&(France)&
&
& & & & & & & & & & & & & & & &&
&
A"Marie"Skłodowska/Curie"Ini4al"
Training"Network"Postgraduate+Research+on+Dilute+Metamorphic+Nanostructures+and+Metamaterials+in+Semiconductor+Photonics++
1st year 2nd year 3rd year
• Design&of&samples.&
• Adequate&
hydrogena)on&
values.&
• Fabrica)on&of&site/,&size/,&and&
shape/controlled&
nanoscale&LEDs&
emi[ng&at&the&
desired&wavelengths.&
• Integra)on&of&nanostructures&&in&
the&
telecommunica)on&
industries&for&
prac)cal&implementa)ons.&
Strategic+plan+for+my+PhD+
A"Marie"Skłodowska/Curie"Ini4al"
Training"Network"Postgraduate+Research+on+Dilute+Metamorphic+Nanostructures+and+Metamaterials+in+Semiconductor+Photonics++
Acknowledgement+&+Collabora=ons+
A"Marie"Skłodowska/Curie"Ini4al"
Training"Network"Postgraduate+Research+on+Dilute+Metamorphic+Nanostructures+and+Metamaterials+in+Semiconductor+Photonics++
Appendix&
A"Marie"Skłodowska/Curie"Ini4al"
Training"Network"Postgraduate+Research+on+Dilute+Metamorphic+Nanostructures+and+Metamaterials+in+Semiconductor+Photonics++