Solid state transformation of the crystalline monohydrate (CH3NH3)PbI3(H2O) to the (CH3NH3)PbI3 perovskite

Article abstract of DOI:10.1039/c5cc03741g

Colorless crystals of (CH₃NH₃·H₂O)PbI₃ spontaneously lose water at 298 K which triggers a transformation to the black (CH₃NH₃)PbI₃ perovskite in the solid state as a porous microcrystalline solid with nanoscale substructure, but the dihydrate (CH₃NH₃)₄PbI₆·2H₂O) requires much more forcing conditions to produce (CH₃NH₃)PbI₃.

Full text of DOI:10.1039/c5cc03741g

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COMMUNICATION
Solid state transformation of the crystalline monohydrate
CH NH )PbI (H O)) to the (CH NH )PbI perovskite
(
3
3
3
2
3
3
3
Gregory H. Imler, Xia Li, Bolei Xu, Graham E. Dobereiner, HaiꢀLung Dai, Yi Rao*, and Bradford B. Wayland*
Received xxxxx, Accepted xxxxx Cite this: DOI: 10.10/x0xx00000x 39
Colorless crystals of (CH NH •H O)PbI spontaneously
Crystals of
1
ꢀ
3
were prepared by reported aqueous
3
3
2
3
2
3ꢀ25
lose water at 298K which triggers a transformation to procedures
the black (CH NH )PbI perovskite in the solid state as and single crystal Xꢀray diffraction (SI).
and the structures verified using powder
Aqueous
3
3
3
a
porous microcrystalline solid with nanoscale solutions of PbI
2
and CH
3
NH
3
I provide a facile route
substructure, but the dihydrate (CH NH ) PbI •2H O) through which the solids of
1
,
2
and
requires much more forcing conditions to produce interconvert. An equilibrium mediated by the aqueous
CH NH )PbI .
solution is established between the solids of and when
3 are able to
3
3 4
6
2
(
1
2
3
3
3
they are both in contact with an aqueous solution saturated
with the PbI /CH NH I reaction mixture (eq. 1). Placing
The optoelectronic properties of methyl ammonium
lead triꢀiodide (CH NH PbI ( )) with a 3ꢀD perovskite
type structure have permitted fabricating several solar cell
2
3
3
1
3
3
3
CH
NH
PbI3(s) + H
O
2
(CH NH •H O) PbI3(s) 1)
3 3 2
3
3
(l)
1
ꢀ22
architectures that have high conversion efficiencies
the black perovskite crystals back into contact with the
mother liquor reaction solution at 298K resulted in
disappearing and crystals of appearing. Crystals of and
3 were also grown from solutions of PbI and CH NH I in
γꢀbutyrolactone (GBL) in the absence and presence of
water respectively, but no conditions were found that gave
which has sparked a surge of research on this material.
Aqueous solutions of PbI and CH NH I can alternately
1
2
3
3
2
1
produce crystals of the black anhydrous 3ꢀD perovskite
2
3
2
3
3
CH NH PbI
(
1
) ,
a nearly colorless monohydrate
3
3
3
3
5
2
4
(
(
(CH NH )PbI •H O) (
2
)
and a light yellow dihydrate
3
3
3
2
2
5
(CH NH ) PbI •2H O) (3) depending on the temperature
3
3 4
6
2
crystals of the monohydrate
2 in GBL.
and solution composition. The optoelectronic properties of
1
are of far greater interest than
2
and
3
because of the
2
3
24
25
Structures of
arrays of PbIn
1
,
2
and
3 have 3ꢀD , 1ꢀD and 0ꢀD
2
3,26ꢀ28
relatively small band gap of ~1.5 ꢀ 1.6 eV
electronic absorption spectrum of the black compound (1)
and broad
(nꢀ2)ꢀ
respectively (figure 1), where each
Pb(II) is surrounded by six iodides in octahedralꢀlike
structures. Ratios of ionic radii provide a guide for the
capability of ABX materials to produce perovskiteꢀlike
Applying the recently proposed
procedure for estimating the effective ionic radius for
polyatomic ions to the hydrated methyl ammonium
cation ([CH NH •H O] ) gives an estimated effective ionic
radius (r ) of 346nm and tolerance factor (α) of 1.13 (α =
2
9
compared to
2
and
respectively.
addressed the stability of
performance that result from exposure to water and
3
with band gaps of 3.1 eV and
2
4,30
3
.8eV
Several recent studies have
3
1
and the effects on solar cell
3
6,37
3
ꢀD structures.
2
9,31ꢀ34
oxygen.
conversions of crystals of the mono and dihydrates (
into in the solid state that extend and complement recent
studies of the reactions of
This article reports on aspects of the
37
2
,
3)
+
3
3
2
1
2
9
A
1
with water vapor.
(
r +r )/(√ꢀ(rB + r )). The tolerance factor of 1.13 is
A
x
X
substantially outside the range of 0.8 ꢀ 1.0 where 3ꢀD
This journal is © The Royal Society of Chemistry 2012
J. Name., 2012, 00, 1-3 | 1

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DOI: 10.1039/C C0374
Jou5Crnal Na1Gme
perovskiteꢀlike
morphology. Adoption of lower dimensional structures
structures are the most
stable
3
7
+
(nꢀ2)ꢀ
for compounds of [CH NH •H O] with PbIn
is
consistent with the effective size of the hydrated methyl
ammonium cation. Loss of water from generates methyl
ammonium cations ([CH NH ] ) which have a near ideal
3
3
2
2
+
3
3
tolerance factor (α= 0.92) for giving a perovskiteꢀlike 3ꢀD
2
5
structure.
The thermodynamically favored coulombic
lattice energy for the 3ꢀD structure drives the conversion of
2
into 1.
Figure 2: a) Calculated powder pattern of CH NH PbI •H O
3
3
3
2
b
) Powder pattern of CH NH PbI •H O crystal after conversion
3 3 3 2
to CH NH PbI
c) Powder pattern of CH NH PbI •H O crystal
3 3 3 3 2
3
3
a)
b)
c)
after conversion to CH NH PbI and crushed to fine powder d)
3
3
3
Calculated powder pattern of CH NH PbI .
3
3
3
Figure 1: a) 3ꢀD perovskiteꢀlike material CH NH PbI (1) b) 1ꢀD
3
3
3
ꢀ
2
+
chains of [PbI3]2 and cationic [CH NH •H O] units. (2) Hydrogen
3
3
2
bonding network between CH NH and H O shown with blue lines.
3
3
2
c) 0ꢀD structure of (CH NH •2H O)PbI (3) with isolated PbI
3
3
2
6
6
octahedra.
a)
b)
c)
The near colorless crystals of the monohydrate
or vacuum spontaneously lose water in a period of minutes
2 in air Figure 3: Observation of a single crystal of CH NH PbI •H O
3
3
3
2
(2) immersed in paratone oil at 298K in air and the spontaneous
conversion to CH NH PbI perovskite (
1
) recorded at different
3
3
3
to form a black material shown to be perovskite
powder xꢀray diffraction pattern (Figure 2, eq. 2).
1 by the
times
a
) t = 4 minutes
b) t = 48 minutes
c) t = 104 minutes.
(
CH NH •H O) PbI
CH NH PbI
+ H O 2)
3(s) 2 (g)
3
3
2
3(s)
3
3
Light yellow crystals of
air developed a black surface characteristic of the
perovskite over a period of 12 hours. The bulk interior
illustrate how the change from colorless to black of the crystal of
is unchanged (figure 4). Formation of
propagates for a crystal of converting to 1. The
from removes the components of CH NH , HI and
water (eq. 3) and is much slower than forming by loss
of water from (eq. 1). A video showing the formation
of on the surface of is given in the SI. Every effort
should be made to avoid formation of in the preparation
cannot be easily removed
This is best achieved by using
3 ((CH NH ) PbI •2H O) in
3 3 4 6 2
Figure 3 shows images from an optical microscope that
1
3
2
1
3
3
2
1
conversion is retarded by a coating of paratone oil to
permit observation of this transformation over a period of
two hours. Inspection of the conversion from a single
2
1
3
3
crystal of
2 to 1 is illustrated in figure 3 and a video in the
of perovskiteꢀlike
or converted to
1 because 3
SI indicates that the conversion is initiated from points of
1
.
nucleation which then propagate through the entire crystal. rigorously dried solvents and using a minimal ratio of
The complete loss of the characteristic diffraction peaks at CH
NH
I to PbI
.
3
3
2
8
.35° and 10.31° of the monohydrate and appearance of
2
3 3 4
(CH NH ) PbI
6 2
•2H O
3 3 3 3 2
CH NH PbI3(s) + 3CH NH I + 2H O(l) 3)
powder diffraction peaks at 14.18° and 28.46°
corresponding to reflections from the 110 and 220 crystal
planes of
2
3,31
1
show that the conversion process is
quantitative and exclusively produces the 3ꢀD perovskite
(
CH NH PbI (1)) as a polycrystalline material (Figure 2).
3 3 3
a)
b)
c)
Figure 4: Single crystal of ((CH NH ) PbI •2H O) (
3
) placed on
a glass slide and observed under optical microscope at ) 5
minutes ) 12 hours and ) surface of crystal removed with
spatula to reveal intact interior of
3
3 4
6
2
a
b
c
3
.
2
| J. Name., 2012, 00, 1-3
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DOI: 10.1039/C5CC03741G
A
single
crystal
of
was stabilized for xꢀray spontaneous at 298, but formation of
structure studies by immediately coating with paratone more forcing conditions. It is important to avoid the
oil followed by mounting in the XRD instrument at formation of during the preparation of the perovskite
00K. The overall structure of consists of 1ꢀD chains because the dihydrate cannot be easily removed or
of [PbI3]2 and 1ꢀD chains of [CH NH •H O] cations converted to 1. The large structural changes and the
the
monohydrate
Solid state conversion for crystals of
2
to
1 is
(
CH NH )PbI •H O)
(
2
)
1
from
3 requires
3
3
3
2
3
1
1
2
3
2
ꢀ
+
3
3
2
with alternating methyl ammonium and water molecules expulsion of water that occur in the transformation from
2
+
ꢀ
held together by hydrogen bonding (Figure 1). Each Pb
interacts with six iodides in a highly distorted octahedralꢀ conversion of crystals of
like array that includes one terminal iodide (figure 1). the long range order and produces a porous microꢀ
The crystal of at 100K shows a diffraction pattern for a crystalline form of The material reported here
single crystal (figure 2). When the crystal of is warmed complements the single crystal and films of previously
the 1ꢀD to the 3ꢀD arrays of PbI units in the solid state
3
2
to the perovskite 1 destroys
2
1.
2
1
to 298K the spontaneous conversion to
spots associated with a single crystal of
1
2
occurs and the utilized in solar voltaic applications.
are replaced by
the circles associated with a powder diffraction pattern Acknowledgments: The authors acknowledge the seed
for
1
(figure 5).
funding from an Energy Frontier Research Center at Temple
University funded by the U.S. Department of Energy, Office
of Science, Basic Energy Sciences under Award # DEꢀ
SC0012575, a Targeted Research Grant from the Temple
University Office of the Vice Provost for Research, and an
instrumentation grant NSFꢀCHEꢀ0923077 for the JEOL JEMꢀ
Figure 5
CH NH •H O)PbI b
3(s)
a
)
Sample single crystal diffraction frame of
) Powder pattern from single crystal of
converted to CH NH PbI and mounted for powder XRD with
1
400 TEM, the CoEꢀNIC facility at Temple University
(
2
3
3
2
founded on DoD DURIP Award N0014ꢀ12ꢀ1ꢀ0777 from
ONR and the expertise of Dr. D. A. Dikin in obtaining SEM
images.
3
3
3(s)
no further manipulation.
The perovskite material (1) obtained from single
crystals of retains the bulk shape of the reactant
crystals, but Xꢀray diffraction (figure 5) and SEM
Figure 6) indicate that a microcrystalline powderꢀlike
material is produced. The loss of one water molecule
from in forming results in a 6% decrease in the unit
cell volume. The SEM images show a porous micron
scale substructure for particles of formed by loss of
water from a single crystal of (figure 6a, figure S1, S2).
Probing the substructure further by TEM suggests that 5ꢀ N.ꢀG. Nanoscale 2011, 3, 4088.
2
Notes and references
Department of Chemistry, Temple University , Philadelphia PA 19122.
a
(
*
Corresponding authors: yirao@temple.edu and bwayland@temple.edu
Electronic Supplementary Information (ESI) available: See
DOI: 10.1039/c000000x/
2
1
(
1)
Am. Chem. Soc. 2009, 131, 6050.
2) Im, J.ꢀH.; Lee, C.ꢀR.; Lee, J.ꢀW.; Park, S.ꢀW.; Park,
Kojima, A.; Teshima, K.; Shirai, Y.; Miyasaka, T. J.
1
2
(
(
3)
T.; Marchioro, A.; Moon, S.ꢀJ.; HumphryꢀBaker, R.; Yum, J.ꢀH.; Moser, J.
which agglomerate into E.; Gratzel, M.; Park, N.ꢀG. Sci. Rep. 2012, 2.
4) Lee, M. M.; Teuscher, J.; Miyasaka, T.; Murakami, T.
N.; Snaith, H. J. Science 2012, 338, 643.
5) Stranks, S. D.; Eperon, G. E.; Grancini, G.; Menelaou,
Kim, H.ꢀS.; Lee, C.ꢀR.; Im, J.ꢀH.; Lee, K.ꢀB.; Moehl,
1
0 nm particles of
state conversion of crystalline
larger particles (figure 6 b, c, figure S3, S4).
1 are initially produced in the solid
2
(
(
C.; Alcocer, M. J. P.; Leijtens, T.; Herz, L. M.; Petrozza, A.; Snaith, H. J.
Science 2013, 342, 341.
(6)
Heo, J. H.; Im, S. H.; Noh, J. H.; Mandal, T. N.; Lim,
C.ꢀS.; Chang, J. A.; Lee, Y. H.; Kim, H.ꢀj.; Sarkar, A.; NazeeruddinMd, K.;
Gratzel, M.; Seok, S. I. Nat Photon 2013, 7, 486.
(
7)
S. I. Nano Lett. 2013, 13, 1764.
8) Stoumpos, C. C.; Malliakas, C. D.; Kanatzidis, M. G.
Noh, J. H.; Im, S. H.; Heo, J. H.; Mandal, T. N.; Seok,
a)
b)
c)
(
Figure 6
from single crystals of
:
a
) SEM of the perovskite material (
1
) obtained Inorg. Chem. 2013, 52, 9019.
(
(
9)
Liu, M.; Johnston, M. B.; Snaith, H. J. Nature 2013,
2
retains the bulk shape of the reactant
5
01, 395.
crystal, and shows the interior structures on the micron scale.
), ) TEM reveals the solid state conversion of crystal of
produces aggregates of 5 ꢀ 10 nm particles of
10)
Chen, Q.; Zhou, H.; Hong, Z.; Luo, S.; Duan, H.ꢀS.;
b
c
2
Wang, H.ꢀH.; Liu, Y.; Li, G.; Yang, Y. J. Am. Chem. Soc. 2013, 136, 622.
(
(
11)
12)
Liu, D.; Kelly, T. L. Nat Photon 2014, 8, 133.
Christians, J. A.; Fung, R. C. M.; Kamat, P. V. J. Am.
1
.
Chem. Soc. 2013, 136, 758.
This journal is © The Royal Society of Chemistry 2012
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View Article Online
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DOI: 10.1039/C C0374
Jou5Crnal Na1Gme
(
13)
H.ꢀS.; Hong, Z.; You, J.; Liu, Y.; Yang, Y. Science 2014, 345, 542.
14) Sum, T. C.; Mathews, N. Energy & Environmental
Science 2014, 7, 2518.
15) Kazim, S.; Nazeeruddin, M. K.; Grätzel, M.; Ahmad,
S. Angewandte Chemie International Edition 2014, 53, 2812.
16) Gao, P.; Gratzel, M.; Nazeeruddin, M. K. Energy &
Environmental Science 2014, 7, 2448.
17) Eperon, G. E.; Stranks, S. D.; Menelaou, C.; Johnston,
M. B.; Herz, L. M.; Snaith, H. J. Energy & Environmental Science 2014, 7,
82.
Zhou, H.; Chen, Q.; Li, G.; Luo, S.; Song, T.ꢀb.; Duan,
(
(
(
(
9
(
18)
M.ꢀJ.; Li, S.ꢀG.; Zhang, Q.ꢀQ.; Yang, L.ꢀM.; Song, Y.ꢀL. Chem. Commun.
015, 51, 1457.
19)
Cheetham, A. K. Chem. Commun. 2015, 51, 6434.
20) Weller, M. T.; Weber, O. J.; Henry, P. F.; Di Pumpo,
A. M.; Hansen, T. C. Chem. Commun. 2015, 51, 4180.
21) Wu, X.; Trinh, M. T.; Niesner, D.; Zhu, H.; Norman,
Z.; Owen, J. S.; Yaffe, O.; Kudisch, B. J.; Zhu, X. Y. J. Am. Chem. Soc.
015, 137, 2089.
22)
Owen, J. S. Nano Lett. 2014, 14, 127.
23) Baikie, T.; Fang, Y.; Kadro, J. M.; Schreyer, M.; Wei,
Cui, X.ꢀP.; Jiang, K.ꢀJ.; Huang, J.ꢀH.; Zhou, X.ꢀQ.; Su,
2
(
Lee, J.ꢀH.; Bristowe, N. C.; Bristowe, P. D.;
(
(
2
(
Choi, J. J.; Yang, X.; Norman, Z. M.; Billinge, S. J. L.;
(
F.; Mhaisalkar, S. G.; Gratzel, M.; White, T. J. Journal of Materials
Chemistry A 2013, 1, 5628.
(
24)
Kanatzidis, M. G. J. Am. Chem. Soc. 2014, 136, 16411.
25) Vincent, B. R.; Robertson, K. N.; Cameron, T. S.;
Knop, O. Can. J. Chem. 1987, 65, 1042.
26) Ball, J. M.; Stranks, S. D.; Horantner, M. T.; Huttner,
Hao, F.; Stoumpos, C. C.; Liu, Z.; Chang, R. P. H.;
(
(
S.; Zhang, W.; Crossland, E. J. W.; Ramirez, I.; Riede, M.; Johnston, M. B.;
Friend, R. H.; Snaith, H. J. Energy & Environmental Science 2015, 8, 602.
(
27)
Meredith, P. Nat Photon 2015, 9, 106.
28) Löper, P.; Stuckelberger, M.; Niesen, B.; Werner, J.;
Lin, Q.; Armin, A.; Nagiri, R. C. R.; Burn, P. L.;
(
Filipič, M.; Moon, S.ꢀJ.; Yum, J.ꢀH.; Topič, M.; De Wolf, S.; Ballif, C. The
Journal of Physical Chemistry Letters 2015, 6, 66.
(29)
Leguy, A. M. A.; Hu, Y.; CampoyꢀQuiles, M.; Alonso,
M. I.; Weber, O. J.; Azarhoosh, P.; van Schilfgaarde, M.; Weller, M. T.;
Bein, T.; Nelson, J.; Docampo, P.; Barnes, P. R. F. Chem. Mater. 2015.
(
30)
Phys.: Condens. Matter 1996, 8, 1217.
31) Christians, J. A.; Miranda Herrera, P. A.; Kamat, P. V.
J. Am. Chem. Soc. 2015, 137, 1530.
32) Niu, G.; Guo, X.; Wang, L. Journal of Materials
Chemistry A 2015, 3, 8970.
33) Frost, J. M.; Butler, K. T.; Brivio, F.; Hendon, C. H.;
van Schilfgaarde, M.; Walsh, A. Nano Lett. 2014, 14, 2584.
34) Bass, K. K.; McAnally, R. E.; Zhou, S.; Djurovich, P.
I.; Thompson, M. E.; Melot, B. C. Chem. Commun. 2014, 50, 15819.
35) Shi, D.; Adinolfi, V.; Comin, R.; Yuan, M.; Alarousu,
Koutselas, I. B.; Ducasse, L.; Papavassiliou, G. C. J.
(
(
(
(
(
E.; Buin, A.; Chen, Y.; Hoogland, S.; Rothenberger, A.; Katsiev, K.;
Losovyj, Y.; Zhang, X.; Dowben, P. A.; Mohammed, O. F.; Sargent, E. H.;
Bakr, O. M. Science 2015, 347, 519.
(36)
Goldschmidt, V. M. Naturwissenschaften 1926, 14,
4
77.
(37)
Kieslich, G.; Sun, S.; Cheetham, A. K. Chemical
Science 2014, 5, 4712.
4
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