Institute of Optoelectronic Systems and …...Jornada de Investigación y Desarrollo Tecnológico - 2003 Institute of Optoelectronic Systems and Microtecnology Enrique Calleja MICINN

Jornada de InvestigaciJornada de Investigacióón y Desarrollo Tecnoln y Desarrollo Tecnolóógico gico -- 20032003

InstituteInstitute ofof OptoelectronicOptoelectronic SystemsSystemsandand MicrotecnologyMicrotecnology

Enrique CallejaEnrique Callejawww.isom.upm.es

MICINN - JST Joint Workshop on “Nanosciences and NewMaterials for Environmental Challenges”

Barcelona,March 10th -12th, 2010

ISOM ISOM -- ETSIT ETSIT -- UPMUPM

Research activity

Magnetic SensorsM

A

NAlGaN + ZnO UV PhotodetectorsNitride-based Solar Cells and IR detectorsWhite light generation with nanoLEDs arraysAlGaN/GaN HEMTs for high frequency and powerAlGaN MEMS/SAW for μW electronics and sensors

GaAs(In,N)-based IR photodetectors (QWIPs)InAs/GaInSbN Quantum DotsInGaAsN/GaAs Heterostructures (1.5 μm)

S Simulation of Non-Metallic Materials


UV-X detectors(Bio / Space)

Blue Laser diodes(Storage/Comms)

RF power transistors(Wireless base stations)

Illumination(White-blue-UV LEDs)

Hydrogen generation(Fuel cells)

High frequency MMICs(Wireless Broadband)

Engine Electronics(Temperature Sensors)

Energy conversion(Photovoltaics)

Switches(Display panels)

MEMS(Pressure sensors)

Wide III-Nitrides applications

Ga(Al,In)N nanorods on Si(111), Si(100), Al2O3 and SiC/Si(111) GaN/Al2O3

AlGaN/Si(111)

GaN/Si(111)

GaN/SiC/Si(111)

III / V << 1

0.5 μm

Growth of III-Nitride Nanorods on Different Substrates

1μm1μm

InN/Si(111)

GaN/Si(100)


Nanorods alignment

Si (111)

GaN [0001]

5 nm

m904

Structural characterization (TEM)

* HRTEM: nanorods without extended structural defects.aligned along the [0001] direction (c)sidewalls are atomically sharp {1100} facets. Strain free.

* SAED: nanorods are structurally uniform and single crystalline.

A. Trampert et al. IOP Conf.Ser. No. 180, 167 (2003).

L Cerutti et al.Appl. Phys.Lett., 88, 213114 (2006).


AlGaN/GaN/AlGaN heterostructure withGaN QDiscs

10 nm

5 nm

c9 unit cells

~46 Å

Al content ≈ 20%

nominal thickness 4 nm

abrupt interfaces

[0001]

[1-100][11-20]

J. Ristic et al., phys. stat. sol. (a), 192, 60 (2002)

J. Ristic et al., Phys. Rev. B68, 125305 (2003)


PL of GaN QDiscs in AlGaN nanorods

AlGaN cap (∝50 nm)

5 GaN QDswith AlGaNbarriers (∝10 nm)

320 nm

190 nm

3,2 3,4 3,6 3,8 4,0 4,2 4,4

m1090(2 nm)3.763 eV

3.591 eV

3.457 eV

m1096(4 nm)

m1085(3 nm) m1077

Ref. AlGaN

3.303 eV

x5

m1079(6 nm)

4.048 eV

Ar+SHG1mW8.5K

100μm

PL In

tens

ity(a

.u.)

Energy (eV)

Blue shift with decreasing QDisc thicknessQuite broad lineshapeStrong QCSE

PL intensity quenching due to Strain ConfinementJ. Ristic et al. Phys. Rev. B72, 085330 (2005).


Nanocavity with Bragg Reflectors

GaN

AlN

AlNAlGaN

GaN QDs

J. Ristic, et al.,Phys.Rev.Lett., 94, 146102 (2005)

Nanocolumnar Homojunctions

Au:Be upper p-type contact (150 nm)

⇒ photolitography, reactive ion etching

EL spectrum dominated by Mg- related emission

p-n junction

m979d1 λS= 500 nm @ RT

m979d1

λS=380 nm @ 8K

m979d2

Cyan

Violet


InN Nanorods on c-plane (Si(111)) and a-plane (a-GaN/r-Al2O3)

0.57 0.60 0.63 0.66 0.69 0.72 0.75

13 K 25 K 35 K 45 K 70 K 90 K

PL

Inte

nsity

(arb

.uni

ts)

Energy (eV)0 15 30 45 60 75 90 105 120 135 150 165 180

0.0

0.5

1.0

1.5

2.0

2.5

3.0

E2

Inte

nsity

(cts

/s)

Angle (º)

InN NCs on a-plane GaN GaN template (a-plane) InN NCs grown along the c-axis

J. Grandal et al. APL 94, 221908 (2009)


Growth selectivity V/III ratio ~ 1500Constant diameter with pulsed MOCVDS.D. Hersee et al. Nanoletters, 6, 8, 1808 (2006)

Ordered GaN and InN nanorods

SiN nanohole mask

Y. Y. NanishiNanishi et al. et al. JpnJpn. J. . J. ApplAppl. Phys. 47, 5330 . Phys. 47, 5330 (2008)(2008)

GaNGaN template patterned by FIBtemplate patterned by FIB

H. Sekiguchi et al., Appl. Phys. Express 1, 124002 (2008)

Integrated PL intensity ratio 4/300K = 81%

Phosphor-free MBE grown white NanoLEDs

Emission from InGaN/GaN nanoLEDs grown on different Ti- nanoholes (same wafer)


Core/Shell Nanowire LEDs by MOVPE

M. Lieber et al., Nano Lett., 4, 1975 (2004)

Growth process

I-V curve of a n-GaN/InGaN/p-GaN NW. Shell is etched by FIB for electrical contact

M. Lieber et al., NanoLett., 5, 2287, (2005)

1, 10, 20, 25, 35% In


Nanrods merging


Nano ELOG

Z. Bougrioua et al. Journal of Crystal Growth 309, 113 (2007)

• Crystalline Si current commercial concentrators typically ~25%. CHEAP.• High efficiency (~35%) for III-V/Ge multi-junctions. EXPENSIVE.

• III-nitrides have very strong band edge absorption coefficients (105 cm-1).• Active region of few hundreds nanometers, instead of hundreds of microns for Si.• Low carrier effective mass, high mobilities, and peak/saturation velocities.• Radiation tolerance for high efficiency solar cells used in outer space. • Easy to grow as thin films or ordered nanorods on cheap Si substrates.• Possibility to grow Nitride-cells on already fabricated Si-cells.• Spontaneous and piezoelectric internal fields beneficial for PV (carrier separation).• Use of InN/InGaN Quantum Wells (QWs) as “i” regions in p-i-n structures• Theoretical efficiencies > 40% with InGaN cells (3J + concentrator) • P-doping problems in InGaN with In%>50%. Japanese activity at Ritsumeikan U.

Photovoltaics using InGaN

� The direct energy gap of InGaN covers most of the solar spectrum


In(Ga)N Nanowires and films grown on Si by MBE

(a) InN nanowire arrays grown on Si substrate by MBE. (b) The epitaxial interfacebetween the InN nanowire and Si where an AlN buffer layer was used

GaN

InGaN

200 nm

100-400 nm

I-V and Photovoltaics in InGaN/Si Nanorods

In-situ nanoprobe I-V by AFM

100 nm

tungstenprobe

InGaN

/ GaN

Si substrate

calculated

Si substrateBand Alignementproviding a tunel junction

Prediction: high PV efficiency in a double InGaN/Si junction .

Approaches

InGaN-based solar cells on sapphireor Silicon using thin films (In)GaN-based solar cells on Si

using Nitride Nanorods(Tang. NanoLetters, 8, 12, 4191 2008)

or Si


• Solar Energy Materials Research Group, Lawrence Berkeley National Laboratory. Prof. W. Walukiewicz

• Nanophotonics Center, Arizona State University. Dr. Y.H. Zhang• Electro-Optics and Photonics Division, Army Research Labs. Dr. G.

Wood• “Very High Efficiency Solar Cell” (VHESC) DARPA programme

• School of Science and Eng. Ritsumeikan Univ. Japan. Prof. Y. Nanishi.

Activity in the Field:

Author Year Journal Fill Factor In (%) Eff (%){Int.}Liou 2009 Jap. J. Appl. Phys. 48,72201 89.5 to 91.8 60-90 33-38

Horng 2009 IEEE Electron Dev. Lett. 30, 021414 55-80

Sheu 2009 IEEE Electron Dev. Lett. 30, 2012275 0,25 58

McCormick 2009 MRS Bulletin 30, 151

Dahal 2009 Appl. Phys. Lett. 94 30 40-60

Tang 2008 Nano Letters 8, 4191 2,7

Chen 2008 Phys. Status Solidi (a) 205, 1103 61 0-30

Neufeld 2008 Appl. Phys. Lett. 93, 143502 75 12 60% EQE @390nm

Zimmler 2007 Nano Technology

Yang 2007 Phys. Status Solidi (a) 204, 4288 57 15-18

Jani 2007 Appl. Phys. Lett. 91, 132117 4-5

Hamzaoui 2005Solar Energy Mater. & Solar Cells 87, 595

28 (2J) to 40 (6J) calculated

Jani 2005 IEEE PV Specialist Conf 20057, 40 {~20}

Yamaguchi 20032003 International Symposium on

Compound Semiconductors42 100 50



Japanese-Spanish Cooperation

• ISOM-UPM. Prof. E. Calleja.• Universidad Autónoma de Madrid. Prof. J.M. Calleja• Instituto Jaume Almera, Barcelona, CSIC. Prof. L. Artús• School of Science and Eng. Ritsumeikan Univ. (Japan). Prof. Y. Nanishi

Common Activities: “High efficiency InGaN heterojunction Solar Cells grown by MBE”Coordination Action within the “Strategic Japanese-Spanish Cooperative Program”MICINN, PLE2009-0023. 2009-2012.

Japanese-Spanish-German Joint Workshop on Advanced Semiconductor Opto-electronic Materials and Devices. Since 2000. Next Edition in Madrid, March 2011.

• ISOM-UPM. Prof. E. Calleja.• School of Science and Eng. Ritsumeikan Univ. Japan. Prof. Yasushi Nanishi• Sophia University, Tokyo, Japan. Prof. Katsumi Kishino• Chiba Univ. Chiba, Japan. Prof. Akihiko Yoshikawa

Common publicationsVisit of Prof. Y. Nanishi to ISOM and Jaume Almera Institute, CSIC. (2008)Visit of Prof. K. Kishino to ISOM on March 23rd (2010)

Documents

Institute of Optoelectronic Systems and …...Jornada de Investigación y Desarrollo Tecnológico - 2003 Institute of Optoelectronic Systems and Microtecnology Enrique Calleja MICINN