semiconductor nanowires and their interface ... - ieee sisc
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LARS SAMUELSONNanoLund and Solid State Physics, Lund University, Lund, Sweden
and Electronics ApplicationsSemiconductor nanowires and their interface proper-ties enabling photovoltaics and lighting applications
48 IEEE Semiconductor Interface Specialist Conference, San Diego, Dec, 6-9, 2017 th
NanoLund and Solid State Physics, Lund University, Lund, Swedenalso CSO for QuNano AB, Sol Voltaics AB, Glo AB & Hexagem AB
LARS SAMUELSON
- What are Nanowires (NWs) & for what?
- A materials idea turned into a technology
- Radial NW-LEDs for RGB micro-LEDs
- c-oriented dislocation-free platelets of InGaN for Blue, Green and Red LEDs
- Outlook for different applications of c- oriented dislocation-free GaN wafers
- NW-based Photovoltaics including Aerotaxy + up-scaling nm-to-meters
- Outlook
Semiconductor nanowire approaches for opto-electronics and energy applications
48 IEEE Semiconductor Interface Specialist Conference, San Diego, Dec, 6-9, 2017 th
What are Nanowires?
Narrow (20 -150 nm) and long (1 - 10 µm) rod-like single crystalline structures formed via self-assembly
1 µm
CBE-grown InAs nanowire: 10 µm long and 55 nm in diameter (Linus Fröberg)
MOCVD-grown GaN nanowire: 3 µm long and ≈ 400 nm in diameter, including radialpn-junction formed ona 100-150 nm core (Zhaoxia Bi)
Seeded by size-selected Au nanoparticles in a VLS growth mode.
Formed by selective area growth of core,followed by radial pn-junct + QW growth
What are Nanowires?
Historical stage: in the 60’s: Ellis et al., Bell Labsin the late 80’s/early 90’s: Hiruma et al., Hitachi Res. Labin the late 90’s: Lieber et al., Harvard University
“Heteroepitaxial ultrafine wire- like growth of InAs on GaAs”Appl Phys Lett 58,1080 (1991) “Vapor-Liquid-Solid Mechanism
of Single Crystal Growth”Appl Phys Lett 4, 89 (1964)
Kenji Hiruma
What are Nanowires?
Historical stage: The early pioneers in the field of whiskers and nanowires
Control & understanding of mechanisms of nanowire growth
Early stage or our research: 2000 :
Ann Persson et al.Nature Materials 2004
Kimberly Dick et al.Nature Materials 2004
Kimberly Dick et al.Nano Lett 2006
NW TREE-structures
VLS vs VSSgrowth mode
InAs
InAs
InP
What are Nanowires?
Historical stage: The early pioneers in the field of whiskers and nanowires
Control & understanding of mechanisms of nanowire growth
Early stage or our research: 2000 :
Ann Persson et al.Nature Materials 2004Mikael Björk et al., Nano Letters 2002
VLS vs VSSgrowth mode
Ultra-abrupt 1D heterostructures
Atomically sharp heterostructures for physics & devices
What are Nanowires?
2000 :
Medium stage development: 2003 :
Basic growth & heterostructures
Technology: Guided self-assembly
Early stage or our research:
Historical stage: The early pioneers in the field of whiskers and nanowires
Thomas Mårtensson et al., Nanotech. 2003; Nano Letters 2004
Demonstration of the combination of top-down-patterningand planar processing with bottom-up growth of arrays ofNWs - also developed for III-Vs & III-Nitrides on Si
What are Nanowires?
2000 :
Medium stage development: 2003 :
Basic growth & heterostructures
Technology: Guided self-assembly2005 : NWs in Biology, Physics & Electronics
Early stage or our research:
Historical stage: The early pioneers in the field of whiskers and nanowires
Niklas Sköld et al.Nanotechn. 2010
Claes Thelander et al.Materials Today 2006IEEE El. Dev. Lett. 2008
Carina Fasth, Andreas Fuhrer et al.Phys. Rev. Lett. 2007
What are Nanowires?
2000 :
2003 :
Basic growth & heterostructures
Technology: Guided self-assembly2005 : NWs in Biology, Physics & Electronics
Recent stage development: 2008 : NWs for LEDs with RGB capability2009 : NWs for Photovoltaics
AEROTAXY - “Flying Wires”
Medium stage development:
Early stage or our research:
Historical stage: The early pioneers in the field of whiskers and nanowires
2011 :
Jesper Wallentin et al.Science 2013
Magnus Heurlin et al.Nature 2012
Bo Monemar et al.Semic.& Semimet. 2016
NanoLund and Solid State Physics, Lund University, Lund, Swedenalso CSO for QuNano AB, Sol Voltaics AB, Glo AB & Hexagem AB
LARS SAMUELSON
- What are Nanowires (NWs) & for what?
- A materials idea turned into a technology
- Radial NW-LEDs for RGB micro-LEDs
Semiconductor nanowire approaches for opto-electronics and energy applications
48 IEEE Semiconductor Interface Specialist Conference, San Diego, Dec, 6-9, 2017 th
Atleast25%ofglobalelectricityisspentforLigh7ng&Displays
GloUSAInc.Sunnyvale,US
R&Dandoperations
GloABLund,SwedenAdvancedR&D
GloAsiaTokyo,Japan
Businessdevelopment
Filtering & removal of threading dislocationsby nm-sized openings in a SiNx mask
CONFERENCES
+ EXPO
glōTM nLEDs&
contact
p-typelayers
n-typecore
quantumwell
growthmask
seedcrystal
GloProprietaryandConfiden7al
glōTM
Cathode
Anode
•p-spreading contact
CHAPTER SEVEN
Nanowire-Based Visible LightEmitters, Present Status andOutlookBo Monemar*, B. Jonas Ohlsson*,�, Nathan F. Gardner{,Lars Samuelson*,�,1*Solid� State� Physics,� Lund� University,� Lund,� Sweden�†GLO� AB,� Lund,� Sweden�{GLO-USA� Inc.,� Sunnyvale,� California,� USA�1Corresponding� author:� e-mail� address:� [email protected]�
Contents
1. Introduction 2272. Existing Planar LEDs for Visible Light, Brief History, and an Update 2323. Planar Approach Versus Nanowire LEDs 2384. Materials for Visible LEDs 2435. MOCVD Growth of III–V Nanowire LED Structures 2466. Relevant Properties of Nanowires for LEDs 2537. Fabrication Process and Properties of NW-LEDs for Visible Light 2588. Application Areas for NW-LEDs: Displays and SSL 266Acknowledgments 267References 267
1. INTRODUCTION
The� increasing� environmental� concerns� during� the� last� decades� have�
inspired� a� development� of� more� energy� efficient� applications� employing�
electricity.� One� such� area� is� general� lighting,� including� indoor� lighting� in�
homes� and� offices,� and� outdoor� illumination� in� streets� and� other� public� areas.�
An� estimated� 20%� of� all� electricity� consumption� in� developed� countries� is�
presently� used� for� lighting� applications.� The� most� efficient� of� the� present�
main� lighting� solutions� (based� on� fluorescent� tubes)� has� about� 25%� conver-
sion� of� electric� power� into� visible� light.� An� improvement� of� the� lamp� effi-
ciency by� a� factor 2 would� thus� save� as� much� as� 10% of� the� world’s� electricity�
consumption.� Considering� that� the� production� of� electricity� in� the� most�
Semiconductors and Semimetals,� Volume� 94� # 2016� Elsevier� Inc.�ISSN� 0080-8784� All� rights� reserved.�http://dx.doi.org/10.1016/�bs.semsem.2015.10.002�
227
ØDiscretesub-pixelsforred,greenandblue
ØDiesizesfrom20µmdownto(ul'mately)5µmorless
Ø Poten'alfor-o Bestpowerefficiency
• comparedtopc-conversion;comparedtootherdisplaysolu'ons(e.g.,oLED)
o Bestcolorgamutsolu'ons• broadflexibilityinemiOngwavelengths
ØHaspoten'altobethebiggestarealdriverforGaNLEDproduc'ono è Andsointhelongrun,itwillstronglyinfluenceSSLtechnology
Emergent“DirectView”DisplaysBasedonMicro-LEDsAkillerapptodrivedevelopmentofdirect-emi3ngLEDs
Drivenbywearablesandnewapplica1ons
Smartwatch,phone,AR/VR,etc…
NanoLund and Solid State Physics, Lund University, Lund, Swedenalso CSO for QuNano AB, Sol Voltaics AB, Glo AB & Hexagem AB
LARS SAMUELSON
- What are Nanowires (NWs) & for what?
- A materials idea turned into a technology
- Radial NW-LEDs for RGB micro-LEDs
- c-oriented dislocation-free platelets of InGaN for Blue, Green and Red LEDs
Semiconductor nanowire approaches for opto-electronics and energy applications
48 IEEE Semiconductor Interface Specialist Conference, San Diego, Dec, 6-9, 2017 th
Buffer/templatecompositions
QW emission wave-lengths
Intention: form c-plane templates of dislocation-free wafers/platelets having the lattice constants allowing optimal Green- & Red-emitting LEDs.
Intention: form templates for c-plane nano-devicessapphire
GaN seed-layer
GaN nanowire GaN c-oriented platelet
InGaN pyramid InGaN c-oriented platelet
GaN seed nucleated
GaN seed nucleated
transformedinto
transformedinto
Growth of InGaN-layer Growth of InGaN QWs Growth of InGaN barrier
Intention: form templates for c-plane nano-devices
InGaNgrowth
In:19%(PL)13%(XRD)
InGaN
XSEM
Othercondi1ons:-GT800C-NH31slm-TEG/TMI106/225-H2:700cc
The challenge of forming perfect ternary InGaN pyramids
GaNseed
SuitablyfacebedGaN-seed
Controlled crystal reshaping of nanostructures
Reshaping
OriginalInGaNpyramidscan,viain-situprocessing, betransformedintoflatInGaNwithc-orientedtop-facets
Layer-by-layerofthetoppor'onofthepyramidareturnedintomobilephysisorbedspecies,migra'ngtoalterna'vefacetsthatofferstableposi'ons,leadingtoshapetransforma'onandthedevelopmentofc-orientedand,s'll,disloca'on-freeplatelets.
Transformation of InGaN pyramids into InGaN platelets
In0.18Ga
0.82N
as-grownpyramids reshape platelets
In0.10Ga
0.90N
RT-PL
GaN
In:0
In:10%
InGaN platelets with increasing In and wavelengths
In:18%
Based on a unique NW-technology we can nowfabricate dislocation-free GaN and InGaNwafers, enabling alsoRED LEDs to be madeusing III-Nitrides, a“Holy Grail” for direct-view display applications
Green and Red InGaN LED-emission
NanoLund and Solid State Physics, Lund University, Lund, Swedenalso CSO for QuNano AB, Sol Voltaics AB, Glo AB & Hexagem AB
LARS SAMUELSON
- What are Nanowires (NWs) & for what?
- A materials idea turned into a technology
- Radial NW-LEDs for RGB micro-LEDs
- c-oriented dislocation-free platelets of InGaN for Blue, Green and Red LEDs
- Outlook for different applications of c- oriented dislocation-free GaN wafers
Semiconductor nanowire approaches for opto-electronics and energy applications
48 IEEE Semiconductor Interface Specialist Conference, San Diego, Dec, 6-9, 2017 th
UV/AlGaNRF/GaN
Power/GaN
Controlled crystal reshaping of nanostructures
Reshaping
Transformation of GaN nanowires into GaN platelets
RF technologies and market segments
“Above 3 GHz for high-power RF, GaN is generally a no-brainer” Lance Wilson, Research director ABI Research
Generally agreed that GaN will dominate in the future
RF electronics - Applications
Telecom BTS
Wireless backhaul Cable TV/Internet
VSAT Defense
Power electronics - Applications
Approaches to fabricate high-quality GaN wafers
GaNonSi GaNonAl203 GaNonSiC GaNonGaN Nanowire-basedGaN
6’’Cost ~$1000 LEDApplica'ons ~$4000* Prohibi've ~$1000
Defects 10^9/cm2 10^8/cm2 10^7/cm2 10^4/5/cm2 Zero*Normalizedto6inch
(Cree2012)(nobelprice.org¨-Nakamura)
NanoLund and Solid State Physics, Lund University, Lund, Swedenalso CSO for QuNano AB, Sol Voltaics AB, Glo AB & Hexagem AB
LARS SAMUELSON
- What are Nanowires (NWs) & for what?
- A materials idea turned into a technology
- Radial NW-LEDs for RGB micro-LEDs
- c-oriented dislocation-free platelets of InGaN for Blue, Green and Red LEDs
- Outlook for different applications of c- oriented dislocation-free GaN wafers
- NW-based Photovoltaics including Aerotaxy + up-scaling nm-to-meters
Semiconductor nanowire approaches for opto-electronics and energy applications
48 IEEE Semiconductor Interface Specialist Conference, San Diego, Dec, 6-9, 2017 th
Data from 3 years of theAMON-RAFP7-proj wtarget 10%
Sing/dual/triplejunct1-sun18%
35%
Nanowire ArraySolar Cells may deliver 18-35%at cost level of Thin-Film cells
“State-of-the-art” ≈ 3.8%
Lars Samuelson, Lund, Sweden: “Nanowire Array Solar Cells”, 28th EU PVSEC, Paris, 2013
- may bring to the market single-Xtal III-V solar cells to the cost of Thin Films
Nanowires-2013, Weizmann Institute of Science, Rehovot, Israel, November 12-15, 2013
Nanowire Array Solar Cells
AMON-RA EU-funded FP7-project: Lund Univ., Univ. Kassel, Fraunhofer ISE, Sol Voltaics AB: “device simulation, nano-imprint lithography, growth, processing, system evaluation”
!
Nanophotonics and ideal wave- guiding permits reduction to ≈ 10% of surface coverage,+ huge angular capture
Concentrator PVpartly achieved by nanophotonics
Materials use is very small, withhigh absorption in direct band-gap materials.Still issue withcost of InP..
AMON-RA High-light: EFFICIENCY OF NW-ABSORPTION EVENFOR LOW COVERAGE
.. we find that 2 µm nanowires in a pitch of 400 nm can absorb 94% of the incident light, light which in a simple ray-optics description would be travelling between the nanowires.
Nanowire peel-off technology developedby Alireza Abrand in a Master-project
FROM ABSORPTION: EFFICIENCY OF NW-ABSORPTION EVENFOR LOW COVERAGE
the efficiency increases by approxi-natekt 1% (relative) for 30° tilt, compared with normal incidence.
the efficiency of the NW array solar cell at 60° tilt is still 95% of the efficiency at normal incidence.
this can, for small tilt angle, more than compensate for the decrease in the in-coming power over the cell with tilt.
NW ARRAY SOLARCELLS ARE HIGHLYEFFICIENT AT GA-THERING DIFFUSEOR TILTED INCI-DENT LIGHT
Total budget 4.35 M€
GaAs based thin film of NWs positioned on top of standard Si PV cell, as 4-terminal Tandem configuration:
- GaAs PV efficiency- cost for III-V NWs
Critical, but solved, issues:
Invited talk at IEEE PVSC-42 inNew Orleans, June 14-19, 2015
15.3 % efficiency
TraditionalNW growth
Generally accepted notion:NWs grow guided by the Xtal structure of the substrate on top of which the NW nucleates.
The crystalline structure & orientation then governs the structure & orientation of the resulting NWs!
(111)
AEROTAXY: a revolutionary new way to grow NWs
New approach for substrate-free NW-growth
Growth w/o substrateseeded by Au-particle Would it be possible (a gedanken experiment!)
to initiate NW growth directly nucleated froma catalytic gold-particle, which we somehow are able to hold in a nano-tweezer inside anMOCVD-growth equipment?
(001)(11
1)(111)
50nm Au seedsTg = 525°C
From HRTEM+FFT we can say:- The NWs are perfect ZB, and virtually defect free- Growth direction is <111>B.
- The growth rate is extremely high, >1µm/s, which is up to 50 - 1000 times faster than
for normal epitaxial growth!
New approach for substrate-free NW-growth
AEROTAXY: a revolutionary new way to grow NWs
New approach for substrate-free NW-growth
Aerotaxy technology:Present status In our Gen 3.0 we produce perfectly straight and un- tapered GaAs NWs, 2-4µmand in Gen 3.5 we grow pn-junctions, using two zones
1"µm" 0.5"µm"
NeaSpec'AFM'image''
GaAs p - GaAs nSn-doped
23/11/14
Aerotaxy)Gen)4• Sol)Voltaics’)lab)in)Lund)• Pre9pilot)produc;on)• Up)to)six)growth)stages)• Started)in)October914
Images by Luke Hankin, Sol Voltaics AB
Aerotaxy: Present status
Gen 3.5 (Lund Univ.)
Gen 4+ (Sol Voltaics)
1"µm" 0.5"µm"
NeaSpec'AFM'image''
GaAs p - GaAs nSn-doped
In the Gen 3.5 we can grow pn-junctions, using two zones
RECENT EXPERIMENTS WITH MULTIPLY-SECTIONED AEROTAXYSYSTEM ENABLING FORMATION OF GaAs p-i-n JUNCTIONS
E. Barrigon, O. Hultin, D. Lindgren, F. Yadegari et al.,Sol Voltaics AB and NanoLund, Lund University
Still quite low Voc (≈0.6V),but typical forun-passivatedGaAs
RECENT EXPERIMENTS WITH MULTIPLY-SECTIONED AEROTAXYSYSTEM ENABLING FORMATION OF GaAs p-i-n JUNCTIONS
E. Barrigon, O. Hultin, D. Lindgren, F. Yadegari et al.,Sol Voltaics AB and NanoLund, Lund University
Major Challenge & Opportunity for Nanodevices in Real-World Applications:
How can we bridge the 7 - 9 orders of magnitude from a Nano-device to it’s macro-device and -system allowing for production?
Ourconcept
Atomstonanowires Inkfeedstock Alignment Filmforma8on CellIntegra8on SystemIntegra8on
Aerotaxy Selfassembly Conven'onalfabrica'on
Will enable assembly ofAerotaxy-produced NWsinto m -scale panels forPV & other applications!
2
8”area>95%Align
NanoLund and Solid State Physics, Lund University, Lund, Swedenalso CSO for QuNano AB, Sol Voltaics AB, Glo AB & Hexagem AB
LARS SAMUELSON
- What are Nanowires (NWs) & for what?
- A materials idea turned into a technology
- Radial NW-LEDs for RGB micro-LEDs
- c-oriented dislocation-free platelets of InGaN for Blue, Green and Red LEDs
- Outlook for different applications of c- oriented dislocation-free GaN wafers
- NW-based Photovoltaics including Aerotaxy + up-scaling nm-to-meters
- Outlook - addressing Global Challenges
Semiconductor nanowire approaches for opto-electronics and energy applications
48 IEEE Semiconductor Interface Specialist Conference, San Diego, Dec, 6-9, 2017 th
Research at NanoLund with intentions to tackle Global Challenges
Energy scavenging by efficient and inexpensive solar cell development
!
ENERGY:the earth receives in 1 h the energy influx from the sun correspon-ding to it’s entire annual energy con-sumption!
Research at NanoLund with intentions to tackle Global Challenges
Energy scavenging by efficient and inexpensive solar cell development
Better power devices for transmission, dc-conversion and electrical vehicles
Power electronics - Applications
GaNonSi GaNonAl203 GaNonSiC GaNonGaN Nanowire-basedGaN
6’’Cost ~$1000 LEDApplicaLons ~$4000* ProhibiLve ~$1000Defects 10^9/cm2 10^8/cm2 10^7/cm2 10^4/5/cm2 Zero
*Normalizedto6
(Cree2012)(nobelprice.org
Research at NanoLund with intentions to tackle Global Challenges
Energy scavenging by efficient and inexpensive solar cell development
Better power devices for transmission, dc-conversion and electrical vehicles
*Normalizedto6
Highly efficient LEDs for Human Centric Lighting based on RGB-nLEDs
Research at NanoLund with intentions to tackle Global Challenges
Energy scavenging by efficient and inexpensive solar cell development
Better power devices for transmission, dc-conversion and electrical vehicles
*Normalizedto6
Highly efficient LEDs for Human Centric Lighting based on RGB-nLEDs
UV-LEDs for disinfection and for water purification
1 µm
Research at NanoLund with intentions to tackle Global Challenges
Energy scavenging by efficient and inexpensive solar cell development
Better power devices for transmission, dc-conversion and electrical vehicles
*Normalizedto6
Highly efficient LEDs for Human Centric Lighting based on RGB-nLEDs
UV-LEDs for disinfection and for water purification
Health monitoring via Nano-fluidic lab-on-chip
PI Prof Jonas Tegenfeldt
NorthernEurope’sPrimaryCenterforCompoundSemi-conductor MaterialsScience,Innova1on&Produc1on
ScienceVillageScandinavia
ProNanoFabMaterials
BusinessCenter
LundNanoLab “NanowireFoundry”
CONFERENCES
+ EXPO
Many students, post-docs and colleagues have contributed to this work, e.g.:Jonas Ohlsson, Ann Persson, Linus Fröberg, Phillip Wu, Kristian Storm & Søren Jeppesen in CBE-growth
Magnus Borgström,Patrik Svensson, Zhaoxia Bi, Jessica Bolinsson, Daniel Jacobsson, Alexander Berg, Magnus Heurlin, Jesper Wallentin, Sebastian Lehman, Philippe Caroff, Kenichi Kawaguchi, Enrique Barrigon in MOVPE
Jonas Johansson, Mesoomeh Ghasemi, Kimberly Thelander, Werner Seifert & Stig Stenström in modelling epi
Knut Deppert, Martin Magnusson, Martin Karlsson, Brent Wacaser & Maria Messing in aerosol technology
Thomas Mårtensson, Bernhard Mandl, Patrick Carlberg, Luo Gang & Lars Montelius in patterning techniques
Reine Wallenberg, Lisa Karlsson, Jakob Wagner, Magnus Larsson, Martin Ek & Filip Lenrick in TEM studies
Anders Mikkelsen, Lassana Ouattara, Jessica Eriksson, Emelie Hillner, Rainer Timm, Ulf Håkanson, Martin Hjort, Alexander Fian, Olof Persson, Edvin Lundgren & Jesper N. Andersen in STM & synchrotron studies
Anders Gustafsson, David Lindgren, Neimantas Vainorius, Kilian Mergenthaler & Bo Monemar in PL/CL studies
Andreas Fuhrer, Carina Fasth, Mikael Björk, Claes Thelander, Olof Hultin, Daniel Wallin, Stephanie Reimann, Liney Kristinsdottir, Henrik Nilsson, Kristian Storm & Stefano Roddaro in studies of quantum transport
Claes Thelander, Erik Lind, Ivan Maximov, Reza Jafari Jam, Kristian Storm & Ali Nowzari, in processing
Lars-Erik Wernersson, Hongqi Xu, Martin Persson, Patrik Brusheim, Nicklas Anttu, Mats-Erik Pistol, Zeila Zanolli, Jonas Pedersen & Andreas Wacker in electronic structure calculations, transport & device modelling
Dan Hessman, Niklas Sköld, Gustav Nylund, Vishal Jain and Håkan Pettersson in nano-optical studies
Heiner Linke, Eric Hoffman, Ann Persson, Henrik Nilsson & Sofia Fahlvik Svensson in thermoelectrics
Christelle Prinz, Waldemar Hällström, Henrik Persson, Jonas Tegenfeldt & Martin Kanje in bioscience
THAN
KYOU
FOR YOUR ATTENTION
In 15 years:>1BSEK forNanoscienceat Lund Univ.
In 10 years:>1BSEK forR&D in Glo &Sol Voltaics