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In-depth study of the effect of annealing temperature on the structural, chemical, and optical properties of MAPI thin films prepared by a one-step deposition method

Authors:
Beatriz Estefania Montaño
Beatriz Estefania Montaño
Jose Diaz at Center for Research and Advanced Studies of the National Polytechnic Institute
Jose Diaz
Yuriy Kudriavtsev at Center for Research and Advanced Studies of the National Polytechnic Institute
Yuriy Kudriavtsev
Ismael Cosme at Instituto Nacional de Astrofísica, Óptica y Electrónica (INAOE)
Ismael Cosme
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Abstract and Figures

The goal of this work is to study the effect of annealing temperature Ta on the properties of CH3NH3PbI3 (MAPI) thin films deposited on glass substrate through structural, compositional, and optical characterization. The films were obtained by one-step deposition method in which an anti-solvent drip was implemented with some delay during spin coating of the precursor mixture, followed by thermal annealing to promote solvent evaporation and rapid crystallization of the film. Properties of the perovskite film after thermal annealing were characterized by different analytical methods. The morphology and roughness of the films were studied by scanning electron microscopy and atomic force microscopy. The crystalline phase was characterized by X-ray diffraction. The optical properties were also determined by UV–Vis spectroscopy. Finally, the elemental composition was analyzed by secondary ion mass spectroscopy. In the temperature range of 100–160 °C, variable average grain diameters between ~ 200 and ~ 500 nm were obtained. However, higher post-deposition thermal annealing temperatures produce clusters of PbI2 between CH3NH3PbI3 grain boundaries. XRD measurements showed a decrease in MAPI crystallite size and an increase in PbI2 crystallite size and amount with increasing annealing temperature. In addition, higher Ta results in a modification of the absorption/reflectance spectra and a red shift of an optical band gap. The results of this study can be useful to produce thin films of MAPI with tunable optical and electronic properties for optimizing the performance of photovoltaic devices.
a Schematic illustration of the MAPI thin film fabrication process using one-step spin-coating method with antisolvent dripping. b Photographs of MAPI films at different moments: during and after the deposition (the film is on the substrates port) and after thermal annealing
a Schematic illustration of the MAPI thin film fabrication process using one-step spin-coating method with antisolvent dripping. b Photographs of MAPI films at different moments: during and after the deposition (the film is on the substrates port) and after thermal annealing
… 
Top view SEM of MAPI thin films prepared by one-step spin-coating method with antisolvent step on glass substrates and annealed at different temperatures: a 100 °C (sample A), b 120 °C (sample B), c 140 °C (sample C), and d 160 °C (sample D), and AFM topography images of the perovskite thin films produced at different reaction temperatures: e 100 °C (sample A), f 120 °C (sample B), g 140 °C (sample C), h 160 °C (sample D)
Top view SEM of MAPI thin films prepared by one-step spin-coating method with antisolvent step on glass substrates and annealed at different temperatures: a 100 °C (sample A), b 120 °C (sample B), c 140 °C (sample C), and d 160 °C (sample D), and AFM topography images of the perovskite thin films produced at different reaction temperatures: e 100 °C (sample A), f 120 °C (sample B), g 140 °C (sample C), h 160 °C (sample D)
… 
XRD patterns of MAPI thin films deposited on glass substrate at the following annealing temperatures (from top to bottom): 100 °C (black line), 120 °C (blue line), 140 °C, (red line), and 160 °C (green line). The diamond dots in pink indicate the peaks associated with the MAPI perovskite material and the circle dots in orange indicate the PbI2 phase (Color figure online)
XRD patterns of MAPI thin films deposited on glass substrate at the following annealing temperatures (from top to bottom): 100 °C (black line), 120 °C (blue line), 140 °C, (red line), and 160 °C (green line). The diamond dots in pink indicate the peaks associated with the MAPI perovskite material and the circle dots in orange indicate the PbI2 phase (Color figure online)
… 
20 × 20 micron ToF–SIMS ion images obtained with positive secondary C3H10N⁺ ions (a–d) and PbI⁺ ions (e–h) for MAPI films annealed at 100 °C (a, e), 120 °C (b, f), 140 °C (c, g), and 160 °C (d, h). Bi3⁺ pulsed ion beam with an energy of 30 keV was used for the analysis
20 × 20 micron ToF–SIMS ion images obtained with positive secondary C3H10N⁺ ions (a–d) and PbI⁺ ions (e–h) for MAPI films annealed at 100 °C (a, e), 120 °C (b, f), 140 °C (c, g), and 160 °C (d, h). Bi3⁺ pulsed ion beam with an energy of 30 keV was used for the analysis
… 
SIMS depth profile of a MAPI film annealed at 100 °C measured with secondary positive cluster ions in the CsM⁺ regime (see details in the text)
+3
SIMS depth profile of a MAPI film annealed at 100 °C measured with secondary positive cluster ions in the CsM⁺ regime (see details in the text)
… 
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In-depth study of the effect of annealing temperature
on the structural, chemical, and optical properties
of MAPI thin films prepared by a one-step deposition
method
Beatriz Montan
˜o
1,
* , Jose
´Juan Diaz
2
, Iouri Koudriavtsev
3
, Ismael Cosme
1,4
,
Nikolai Korneev
1
, and Svetlana Mansurova
1
1
Instituto Nacional de Astrofísica, Óptica y Electrónica, INAOE, Luis Enrique Erro # 1, Tonantzintla, C.P. 72840 Puebla, Mexico
2
Programa de Nanociencia y Nanotecnología, CINVESTAV- IPN, Av. IPN 2508 Col. San Pedro Zacatenco, 07360 Mexico City, Mexico
3
Departamento de Ingeniería eléctrica (SEES), CINVESTAV- IPN, Av. IPN 2508 Col. San Pedro Zacatenco, 07360 Mexico City, Mexico
4
CONACYT Research Fellow- INAOE, Luis Enrique Erro # 1, Tonantzintla, C.P. 72840 Puebla, Mexico
Received: 27 October 2022
Accepted: 9 April 2023
Published online:
22 April 2023
ÓThe Author(s), under
exclusive licence to Springer
Science+Business Media, LLC,
part of Springer Nature 2023
ABSTRACT
The goal of this work is to study the effect of annealing temperature T
a
on the
properties of CH
3
NH
3
PbI
3
(MAPI) thin films deposited on glass substrate
through structural, compositional, and optical characterization. The films were
obtained by one-step deposition method in which an anti-solvent drip was
implemented with some delay during spin coating of the precursor mixture,
followed by thermal annealing to promote solvent evaporation and rapid
crystallization of the film. Properties of the perovskite film after thermal
annealing were characterized by different analytical methods. The morphology
and roughness of the films were studied by scanning electron microscopy and
atomic force microscopy. The crystalline phase was characterized by X-ray
diffraction. The optical properties were also determined by UV–Vis spec-
troscopy. Finally, the elemental composition was analyzed by secondary ion
mass spectroscopy. In the temperature range of 100–160 °C, variable average
grain diameters between *200 and *500 nm were obtained. However, higher
post-deposition thermal annealing temperatures produce clusters of PbI
2
between CH
3
NH
3
PbI
3
grain boundaries. XRD measurements showed a decrease
in MAPI crystallite size and an increase in PbI
2
crystallite size and amount with
increasing annealing temperature. In addition, higher T
a
results in a modifica-
tion of the absorption/reflectance spectra and a red shift of an optical band gap.
The results of this study can be useful to produce thin films of MAPI with
tunable optical and electronic properties for optimizing the performance of
photovoltaic devices.
Address correspondence to E-mail: beamon@inaoep.mx
https://doi.org/10.1007/s10854-023-10437-3
J Mater Sci: Mater Electron (2023) 34:1016 (0123456789().,-volV)(0123456789().,-volV)
Content courtesy of Springer Nature, terms of use apply. Rights reserved.
... [21][22][23] Additionally, TOF-SIMS enables the investigation of the degradation processes occurring at these interfaces under different conditions, shedding light on the mechanisms that may impact the long-term stability and performance of perovskite solar cells. 24,25 In this study, we conduct a detailed examination of the interfaces within the device structure using the TOF-SIMS technique. Additionally, we utilize scanning electron microscopy (SEM) to study the surface structure of the interfaces, complementing our understanding of their morphology and characteristics. ...
... These columns were previously identified as PbI 2 crystals and are visualized through the local increase in the yield of methylammonium cluster ions, attributable to the matrix effect . 24,25 In our previous works 24, 25 and other report in literature , 38 the formation of columnar structures was attributed to the heating of perovskite during thermal annealing process. During this process, the perovskite undergoes degradation, leading to the formation of a new phase (PbI 2 ) in the form of crystallites that penetrate throughout the entire perovskite layer. ...
... These columns were previously identified as PbI 2 crystals and are visualized through the local increase in the yield of methylammonium cluster ions, attributable to the matrix effect . 24,25 In our previous works 24, 25 and other report in literature , 38 the formation of columnar structures was attributed to the heating of perovskite during thermal annealing process. During this process, the perovskite undergoes degradation, leading to the formation of a new phase (PbI 2 ) in the form of crystallites that penetrate throughout the entire perovskite layer. ...
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