1. No category

Synthèse et propriétés optiques de pérovskites
pour le photovoltaïque et l’émission de lumière
Emmanuelle DELEPORTE
Laboratoire Aimé Cotton
1
PHOTOGRAPHIE DE L’EQUIPE « NANOPHOT » AUJOURD’HUI Emmanuelle Deleporte (Pr. ENS Cachan) Jean-­‐SébasKen Lauret (Pr ENS Cachan) Pérovskites hybrides Camille Sonneville (ATER) KaKa Abdel Baki (Ph D) Anne Debarre (CNRS) Gaëlle Allard-­‐Tripé (Ingénieur d’Etudes CNRS) Nanotubes de carbone Haytham Zahra (Ph D) Géraud Delport (PhD) Vincenzo Ardizzone (post-­‐doc) Nanospectroscopie Meriem Stamboul (PhD) Khaoula Jemli (PhD) Hiba Diab (PhD) 2
Pérovskites hybrides pour l’émission(OLEDs, lasers) et le photovoltaïque (cellules solaires) En collaboraKon étroite avec Pierre Audebert (Pr ENS Cachan PPSM) (CH3NH3)PbI3 Laurent Galmiche (Ingénieur d’Etudes ENS Cachan PPSM) (C6H5-­‐C2H4-­‐NH3)2PbI4 7 mm x 5 mm x 3 mm
PMPI
Cristaux Couches minces Nanopar*cules 3
Pas*lles GOALS
LIGHT-MATTER COUPLING
PHOTOVOLTAÏC
QUANTUM OPTICS
Necessity of
Systems which COLLECT light: nano-antennas
Physical analysis of the energy transfers
Role of the interfaces
Systems which EMIT light: microcavities
Polariton lasers
Single photon sources
• Material engineering
• Mastery of the material
• Precise knowledge of the electronic properties
4
OPTICAL EXPERIMENTS
•  Absorption spectroscopy
•  Angle-resolved reflectivity
•  Photoluminescence spectroscopy
•  Microphotoluminescence à Individual object
•  Pump-probe ultrafast spectroscopy (femtosecond)
From the near UV (300 nm) to the IR (1,5 microns) range, from 10K to 300K
Light-matter interaction
Information on the electronic structure of the nanomaterials,
confinement effects, energy transfer
Linear and non-linear optical properties of semiconducting
nanomaterials
Dynamics of electronic interactions
5
Perovskites - Du matériau massif à la structure en couches
perovskite 3D AMX3
: AA
:M
:X
perovskite 2D A2MX4 :
des monocouches de MX6
séparées par des AX
”nos” perovskite hybrides organiqueinorganique :
A : organique (R-NH3 )
M : métal ( Pb)
X : halogène (Cl, Br, I)
perovskite 2D A3M2X7 :
des bicouches de MX6
séparées par des AX
(R-NH3)2MX4
6
Synthesis of 2D-layered perovskites
Collaboration with PPSM ( P. Audebert, L. Galmiche) ENS Cachan
Our perovskites: (R-NH3)2MX4
R :phenyl+alkyl chain ; M : metal ; X: halogen
Step 1: Synthesis
Inorganic salt
(PbI2, PbBr2, PbCl2)
Organic molecules
(synthesis at PPSM)
Solvent
Step 2: Deposition by spin-coating
7
2D-layered perovskite thin films (10 – 100 nm)
Synthesis of 2D-layered perovskites
Effect of the spin-coating
Perovskites in solution
Densité optique (u.a.)
4
(C6H5C2H4NH3)2PbI4
Deposition by spincoating
3
2D-layered perovskites
1,0
2
Densité optique
T = 300 K
0,8
1
0,6
0
1.8 2.0 2.2 2.4 2.6 2.8 3.0 3.2 3.4 3.6 3.8 4.0
Energie (eV)
A sharp peak appears at low energy
(2,40 eV, FWHM = 80 meV à 300 K)
0,4
0,2
0,0
1,8 2,0 2,2 2,4 2,6 2,8 3,0 3,2 3,4 3,6 3,8 4,0
Self-assembled 2D-layered perovskites
Energie (eV)
8
Synthesis of 2D-layered perovskites
X diffraction
L. Largeau, O. Mauguin (LPN)
Molecular crystal
K. Gauthron et al, Optics Express 18 (2010) 5912.
9
Multi-quantum well structure
6 Ǻ 10 Ǻ
Inorganic
layer
Organic
layer
Quantum confinement
+
Dielectric confinement
εp > εb
Eb 220 - 480 meV
Strong excitonic
effects
Observable at 300 K
(kBT = 26 meV)
10
4
Optimization of the spin-coating parameters :
- nature of the solvent, of the substrate, of the solution concentration
- duration, speed and acceleration
Reproducibility of the deposition
Densité optique
Densité optique
1,01,0
dépôt
11
dépôt
dépôt 2
0,80,8
0,60,6
0,40,4
0,20,2
(C6H5-C2H4-NH3)2PbI4
0,00,0
1,81,82,02,02,22,22,42,42,62,62,82,83,03,03,23,23,43,43,63,63,83,84,04,0
Energie
Energie(eV)
(eV)
11
Tunability : influence of M, X and R
Collaboration with PPSM (P. Audebert, L. Galmiche)
(Pb, I) à green
(Pb, Br) à blue, violet
(Pb, Cl) à near UV
(Sn, I) à orange-red
12
7
Tunability : mixed perovskites
(R-NH3)2MX4-xYx
Accordabilité du gap optique
G. Lanty et al, J. Phys. Chem. Lett. 2014
Exciton de Wannier
8
PEPX Photoluminescence
Luminescence at room temperature PL of PEPI, λexc = 405 nm
P h o to lu m in es c en c e
A b s o rb an c e
3.2
3.3
3.4
3.5
3.6
3.7
3.8
3.9
4.0
E ne rg y (e V )
PL of PEPB, λexc = 325 nm
Stokes-Shift: several 10 meV
14
9
CAVITES VERTICALES EN COUPLAGE FORT, POLARITONS: Contexte •  Bose-Einstein condensate (BEC) at solid state
CdTe
ZnO:
LASMEA + CRHEA
2013
J. Kasprzak et al Nature 2006
Figure 1: Fabrication of the fully-hybrid bulk ZnO microcavity.
a, A single-crystal c-ZnO substrate is covered by a HfO2/SiO2 DBR. b, The whole DBR/ZnO substrate is
flipped upside-down and transferred to a glass substrate. c, The ZnO substrate is backside
etched/polished down to a thickness of several tens to hundreds nanometers. d, A HfO2/SiO2 DBR is
deposited on top of the processed ZnO substrate. e, Emission intensity below threshold measured
along the thickness gradient and showing the first five polariton modes (cavity thickness from λ/2 to
5λ/2) .
P. G. Savvidis et al Phys. Rev. Lett. 2000
•  Low threshold polariton
lasers
•  Optical parametric amplifier
Light-matter strong coupling
MICROCAVITY POLARITONS
Planar microcavity:
mirror 1
Active medium
mirror 2
Ex
Eph(k//)
Hk// =
New eigentstates of the system = polaritons
V
2.5
UPB
2.4
UP,k//
LP,k//
= α(k//) ph,k// + β(k//) ex,k//
= - β(k//) ph,k//
+ α(k//) ex,k//
Eex(k//)
2.6
Energie (eV)
Ωext << Ωmod à strong coupling
V
Eexciton
2.3
Ephoton
2.2
LPB
0
2
4
6
k//
8
10
16
12
Light-matter srong coupling
Example of structure
35 nm
50 nm
50 nm
50 nm
Precise control of the position of the
peroskite layer at an anti-node of the
intracavity electric field
Strong coupling regime
G. Lanty, New J. Phys. 10 (2008) 065007.
17
Effet de «bottleneck» (1)
phénomène observé également pour des microcavités
inorganiques sous faible densité d’excitation
18
33
CAVITE: Cavités hybrides semiconducteur/pérovskites POLARITONS HYBRIDES
PMPBàLPB α au produit des
parts relatives à la transition
excitonique de la pérovskite
des deux branches
V. Agranovich, Solid State Comm 1997
Hybrid microcavity ZnO/MFMPB
Collaboration with CRHEA (J. Zúñiga Pérez) et LASMEA (J. Leymarie)
G. Lanty et al, Phys. Rev. B84 (2011) 195449
CAVITE: Cavités à haut facteur de qualité Top mirror
PMMA
Perovskite
SiO2 layer
Bottom mirror (dielectric)
Silica substrate
Dépôt d’un miroir diélectrique
pour fermer la cavité
= Un défi technologique
Top Mirror Migration Method
Développée par Z. Han
High quality factor cavities
Q = 90
New technology of report of the dielectric mirror:
Useful for organic electronics when it is necessary
to combine different technologies
Z. Han et al, Optics Letters 37, 5061, 2012
Z. Han et al, APEX 6 (2013) 106701
Photoluminescence
confinement of zero-dimensional polaritons in perovskite-based mie. Photoluminescence of discrete polaritonic states are observed for
ric sphere-like defects which are spontaneously nucleated on the top
inewidth of these confined states are found much sharper (almost one
of photonic modes in the perovskite planar microcavity. Our results
organic-inorganic cavity polariton in confined microstructure and sugealize integrated polaritonic devices operating at room temperature.
Quantum confinement of zero-dimensional hybrid organic-inorganic
polaritons at room temperature
3
- quasiparticles
final samples as shown in Fig. 1(d). Notice that simietweenlar
quantum
defects have been reported for GaAs based cavities
1], have[17].
emerged
In this case, they were attributed to point-like deundamental
and
fects formed
during the molecular beam epitaxy of the
laritons
provide
top
mirror.
of Bose-Einstein
Confocal microphotoluminescence on single sphere-like
stem [2–6].
defectsOn
is performed at room temperature, using a laser
on [7] beam
and bal(405 nm) focused onto a 1.5 µm spot diameter by a
te in engineered
microscope objective (N A = 0.65). Polariton emission is
new generation
imaged on a CCD camera coupled to a monochromator.
rt microcavities
We first report the study of polariton emission of a
Q-factors as high
representative sphere-like defect in our sample, denoted
th the facilities
D1. techFigure. 2(a) presents the photoluminescence inteny di↵erent
sity
I(x, E) of polariton emission within D1 as a function
he small
exciton
position and energy. We distinguish five discrete poregime of
is limited
modes, which correspond to 0D polaritons within
or roomlariton
temperthe matedefect due to confinement of the photonic compoented into
We use the method proposed by Zajac et al [17]
gy suchnent.
as GaN
to calculate the potential confinement of these polarirganic-inorganic
tons.BoseOur hypothesis is that D1 is perfectly symmetalthough
rictemperand all physical quantities only depend on the radial
at room
distance
6, 29, 30],
no po-r. We denote by n (r), the wave function of
th
confined state and by In (r) its photoluminesrature the
has nbeen
FIG.
1. (a) Di↵erent
steps of the
samplefrom
fabrication. (b)
ed withcence
the patemission
intensity.
In (r) is extracted
directly
microscopy image of an ensemble of sphere-like defects
l as thethe
fragility
intensity Optical
of polariton
emission in real space I(x, E):
FIG. 3. Far field emission intensity measured in D1. Inset:
on the top Bragg mirror. (c) SEM image of a sphere-like
fore anInobstacle
(r) / I(|x|defect
= r, E
=
E
).
The
spectrally
integrated
n
Integrated
photoluminescence intensity as a function of enin the top Bragg mirror before the release from
its
nic device
operdensity
of confined
states
D(r)
is
given
by:
ergy.nm.
substrate, having a diameter of 900 nm and height of 300
MEB
images
H.S. Nguyen et al, APL 2014
Q = 750!
Bien connaître le matériau
Chimie du matériau: -­‐  Propriétés de self-­‐assemblage -­‐  Différentes formes -­‐  AmélioraKon du photobleaching -­‐  FoncKonnalisaKon, nano-­‐antennes Physique du matériau: -­‐  Structure de bandes -­‐  Propriétés excitoniques -­‐  Accordabilité du bandgap -­‐  Pompe-­‐sonde: propriétés de relaxaKon 25
Improvement of the
luminescence efficiency and of
the self-organization ability
(R- (CH2)n-NH3)2PbX4
Change of:
• flexibility of the ring R
• steric encumbrance of the
ring R
• length of the alkyl chain: n
S. Zhang et al, Acta Materiala 57 (2009) 3301.
26
Different forms
8 mm x 4 mm x 15 mm
7 mm x 5 mm x 3 mm
•  Crystal bulks:
–  Evaporation of solution
–  Slow solution exchange
PEPI
PMPI
•  Nanoparticles:
–  Spray-drying method
–  Solution method (PbI2 nanoparticles
reacting with corresponding ammonium salts)
Luminescence of
nanoparticules :
(Spray-­‐drying) P. Audebert et al. Chem. Mater., 21 (2):210–
214, 2009.
Transmission Electronic
Microscopy:
Sizes are from 50 to 500 nm
27
27
Improvement of the photobleaching
•  Elimination of halogen species in inorganic parts
Iodine indicator
(a)
(b)
PhotodegradaKon of perovskites with aromaKc ring is due to the aiack by electrophilic radical
Reference Exposed under a 325 nm HeCd laser at 27 mW
CMPI:
I2
Dimerization
PEPI:
Radicalar substitution
28
28
MATERIAU:(AmélioraPon(du(photobleaching(
MATERIAU: AmélioraKon du photobleaching Fluorinated (R-NH
Fluorinated
(R-NH3)2PbI4 perovskites
3)2PbI4 perovskites
Pb
I
N
C
0.8
F
1.0
4FPEPI doped PMMA
4FPEPI doped PMMA
Intensity (Arb.Unit)
Intensity (Arb.Unit)
1.0
0.8
MATERIAU:(AmélioraPon(du(photobleaching(
4FPEPI
(R-NH3)2PbI4 perovskites
0.4
0.6
AFM 50 nm PEPI
0.4
AFM(50(nm(PEPI(
PEPI doped
Fig. 2.PMMA
AFMFig.
images
of (a)
PEPI 10% and (b) p
2. AFM
Roughness
10images
nm of (a) PEPI 10
PEPI doped PMMA
0.2
0.2
4FPEPI doped PMMA
Intensity (Arb.Unit)
Pb
I
N
C
F
1.0
0.6
0.8
0.0
0.0
0
4FPEPI
PEPI
PEPI
∆=
!
N
!
N
1
1
(xi − xave
)
∑
∆=
N i=1
N∑
i=1
where 800
N iswhere
the1200
total
pixels inofeach
AFM
imagA
0 200 400
1600
1800ofnumber
N1400
isnumber
the
total
pixels
in each
Fig. 2. AFM 600
images of1000
(a) PEPI
10%
and
(b)
pfPEPI
doped PMMA.
AFM
300
nm
200 400 600 800 1000
1200
1400
1600
1800of
is2.the
average
height
for10%
each
image.
is fou
x Fig.
AFM
images
(a) PEPI
and AFM
(b) pfPEPI
doped∆PMMA.
ave
height
for PMMA
each AFM imag
Timexave
(s) is the average
AFM(300(nm((
4FPEPI
doped
4FPEPI
thin layer. thin
Thislayer.
valueThis
of ∆ value
represents
25 % of
Timespin-coated
(s)
spin-coated
of ∆ represent
4FPEPI(doped(PMMA
Roughness
1
nm
0.6
an obstacleanto!
the fabrication
of high quality
factor
microc
obstacle
to the fabrication
of high
quality
fac
N
!
1
the realization
of a vertical
microcavity
containingcontaini
a PEPI
Included in a PMMA
matrix
= 4FPEPI
doped
PMMA
2
microcavity
∆ the
= realization
(xi PMMA
− of
x1aveaN)vertical
AFM(50(nm(PEPI(
doped
PMMA
∑
2
Included inPEPI
a PMMA
matrix
=
4FPEPI
doped
Fig.
2.
AFM
images
(a)
PEPI
and
N i=1
mirror,
themirror,
monolithic
deposition
of
∆=
(xideposition
−
xaavetop
) dielectric
∑ of
the
monolithic
of10%
a top mirror
dielec(
N
0.4
i=1
be impossible.
WeiPhys.
et al,J.
D: Appl.
Phys.
(2013)
135105
beinimpossible.
Y. Wei et Y.
al,J.
D: Phys.
Appl. where
Phys.
(2013)
135105
29 at the 19
N 46
is the
total46
number
of pixels
each AFM image, xi the height
ith pixel,
19
where
N
is
the
total
number
of
pixels
in
each
AFM
image,
x
the
height
atillu
thP
In
order
to
improve
the
long-time
stability
under
i
Wei et,Express
Optics Express
20
(2012)height
10401
average
for each AFM
∆ isimprove
found tothe
be 10.5516
nmstability
for the
In image.
order to
long-time
Y. Wei et,Y.Optics
20 x(2012)
10401
ave is the
the This
average
height
for each
AFM
∆ in
is !
found
be 10.5516
ave is
perovskite
active
layer
the
vertical
microcav
spin-coated xthin
layer.
value
of ∆
represents
25embedded
%image.
oflayer
the thickness
of to
the
and win
perovskite
active
embedded
in layer
the
vertica
PEPI
thin
layer.
This
value of
∆arepresents
25 % of
thickness
of the
the
l
0.2
N ifby
ovskites
included
inincluded
polymer
Inspired
an obstacle spin-coated
to the fabrication
of high
quality
factor
microcavities:
forthe
example,
we
cons
ovskites
in amatrix.
polymer
Inspire
1 matrix.
MATERIAU: FoncKonnalisaKon, nanoantennes To improve the exciton photogeneration performance: improve the light absorption
Introduce an absorber in the organic part :
= nano-antenna
Inorganic
layer
Organic
layer
solutions of A) Standard
effected from similar concentration
PEPB, B) NAAB casting and C) The NAAB doped PEPB. The
last picture shows that the doped film emits much more light than
the other deposits, including the pure imide itself, the emission of
which displays a low quantum yield in the solid state.
Chromophores
(6) Hong, X.; Ishihara, T.; Nurmikko, A. V. Phys. Rev. B 1992,
45, 6961–6964.
(7) Symonds, C.; Bellessa, J.; Plenet, J. C.; Bréhier, A.; Parashkov, R.; Lauret, J. S.; Deleporte, E. Appl. Phys. Lett. 2007, 90.
Burschka, J.; Pellet, N.; Moon, S.J.; Humphry-Baker, R.;
Gao, P.; Nazeeruddin, M.K.; Grätzel, M. Nature, 2013,
499, 316-319.
(8) Symonds, C.; Bonnand, C.; Plenet, J. C.; Bréhier, A.; Parashkov, R.; Lauret, J. S.; Deleporte, E.; Bellessa, J. New J. Phys.
2008, 10. Liu, M.; Johnston, M.B.; Snaith, H.J. Nature,
Constraints
on the choice of the absorbant
2013, 501, 395-402.
(9) Koutselas,
I.; absorber
Bampoulis, P.; Maratou, E.; Evagelinou, T.;
-  Efficient
UV
Pagona, G.; Papavassiliou, G. C. The Journal of Physical Chem-  Energy
transfer
from the absorber to the perovskite
istry C 2011,
115, 8475–8483.
(10) Chang,
J. A.;steric
Rhee, J.encumbrance
H.; Im, S. H.; Lee, Y. H.; Kim, H.;
-  One
phenyl
Seok, S. I.; Nazeeruddin, M. K.; Gratzel, M. Nano Letters 2010,
-  Binding
between phenyl and ammonium: 1 to 3 alkyl
10, 2609–2612.
Fig 5: Photograph of the three perovskite layers taken under ilThèse
K. Jemli
lumination with a standard
laboratory
lamp (broad band at 360
nm). From right to left: Standard PEPB perovskite layer; NAAB
microcrystal layer and 10% NAAB doped PEPB layer.
(11) Yu, X.; Lei, B.; Kuang, D.; Su, C. Chem. Sci. 2011, 2, 1396–
1400.
(12) Bréhier, A.; Parashkov, R.; Lauret, J. S.; Deleporte, E. Appl.
Phys. Lett. 2006, 89, 171110.
(13) Lanty, G.; Bréhier, A.; Parashkov, R.; Lauret, J.; Deleporte,
E. New J. Phys. 2008, 10, 065007.
(14) Wei, Y.; Lauret, J. S.; Galmiche, L.; Audebert, P.; Deleporte, E. Opt. Express 2012, 20, 10399–10405.
30
Photoluminescence en fonction de la température
PL Intenisty (arb. unit)
Collaboration avec le LPN (J. Bloch, K. Gauthron)
PhE-PbI4
10 K
20 K
40 K
60 K
80 K
90 K
110 K
130 K
150 K
170 K
190 K
210 K
230 K
250 K
300 K
5.0x10-4
4.0x10-4
-4
3.0x10
2.0x10-4
•  Présence de deux
raies
•  Décalage vers le bleu
lorsque T augmente
•  Élargissement et
baisse
d’intensité quand T
augmente
1.0x10-4
0.0
2.28
2.30
2.32
2.34
2.36
2.38
2.40
2.42
Energy (eV)
K. Gauthron et al, Optics Express 18 (2010) 5912
31
Photoluminescence en fonction de la température
PhE-PbI4
(1) Lee et al PRB 33, 5512 (1986)
E a = 60 meV (étude
Integrated PL)
h ωLO = 1 3 , 7 m e V
(phonon dans PbI2) fixé
Γ0 = 17 ± 1 meV
a = 0.03 ± 0.01 meV/K
ΓLO = 70 meV
32
Excitation de la Photoluminescence (2K)
PLE détectées sur les différentes
raies
PL intensity (norm.)
1,0
2K
0,5
0,0
continuu
m
2,4
2,6
Energy (eV)
PLE intensity (arb. unit)
1,0
0,5
0,0
2,8
- “Stoke’s shift” = 7
meV
Ne Varie pas en
fonction de la
température
-  ELiaison = 205 meV
33
Tunability : mixed perovskites
(R-NH3)2MX4-xYx
Accordabilité du gap optique
G. Lanty et al, J. Phys. Chem. Lett. 2014
Exciton de Wannier
34
8
MATERIAU: Pompe-­‐sonde, propriétés de relaxaKon 1,2
P pum p= 0 .2 µW ;P probe = 0 .0 1 µW
λ(probe )= 5 1 7 nm ; λ(pum p)= 4 4 0 nm ;
1,1
0.10
1,0
D eltaT /T at 0 ps
D eltaT /T at 5 ps
D eltaT /T at 30 ps
D eltaT /T at 90 ps
D eltaT /T at 300 ps
D eltaT /T at 600 ps
0.08
0,8
0,7
0,5
4 4 0 nm
4 6 0 nm
4 8 0 nm
5 0 0 nm
5 1 7 nm
0,4
0,3
0,2
0,1
0.04
0.02
0.00
-­‐0.02
2.20
0,0
-­‐0,1
D e lta T /T
0.06
0,6
ΔT n o rm a lis é à 1
0,9
-­‐200
-­‐100
0
100
200
300
R etard en fs
400
500
600
700
2.25
2.30
2.35
2.40
2.45
2.50
2.55
E nerg ie (eV)
• Temps de vie de l’exciton: environ 110 ps
• Forte interaction exciton-phonon (<100 fs)
• Importance des effets de type Auger
• Phase Space Filling / Renormalisation de la fonction d’onde
35
Thèse Katia Abdelbaki, soutenue le 5 décembre, article en cours de rédaction
2.60
THANK YOU
FOR YOUR ATTENTION
36