Synthesis, electronic structure and optical properties of PbBr 1.2 I 0.8

Levkovets, S.I.; Khyzhun, O.Y.; Myronchuk, G.L.; Fochuk, P.M.; Piasecki, M.; Kityk, I.V.; Fedorchuk, A.O.; Levkovets, V.I.; Піскач, Л. В.; Parasyuk, O.V.

doi:10.1016/j.elspec.2017.05.006

Cited by 8 publications

(12 citation statements)

References 26 publications

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“…The peaks at 20.48 • and 22.38 • can be assigned to the (120) and (210) planes of PbBr 1.2 I 0.8 , respectively. In addition, a further increase in the ratio to x = 0.7 produced a mixture of PbBr 1.2 I 0.8 and PbBr 2 , as shown in Figure 1b, which is consistent with the phases predicted by the phase diagram [32]. Very low intensities of the peaks of the two phases are observed, indicating that the phases are made of very fine particles.…”

Section: Resultssupporting

confidence: 83%

“…with the phases predicted by the phase diagram [32]. Very low intensities of the peaks of the two phases are observed, indicating that the phases are made of very fine particles.…”

Section: Resultsmentioning

confidence: 51%

“…It is also noted that the peak corresponding to the (001) plane shifts to the right with the addition of PbBr 2 , as shown in Figure 1b, implying that shrinkage of the lattice occurs in the <001> direction. This may be the result of the inclusion of Br ion, whose size is smaller than that of I ion, into I sites within a solubility limit, approximately 5% of PbBr 2 in PbI 2 [32]. Additionally, by increasing the PbBr 2 concentration above 5%, which is the solid solubility, the peak continues to shift toward the right, representing a continual decrease in the c-value of the PbI 2 unit cell along the c-axis.…”

Section: Resultsmentioning

confidence: 99%

“…Additionally, by increasing the PbBr 2 concentration above 5%, which is the solid solubility, the peak continues to shift toward the right, representing a continual decrease in the c-value of the PbI 2 unit cell along the c-axis. According to the quasi-binary phase diagram [32], two phases consisting of the β phase and intermetallic compound PbBr 1.2 I 0.8 are formed at the molar ratio of 0.05~0.5. However, only β (PbI 2 -rich) single phase and no intermetallic compound was detected by XRD at the ratio of both 0.1 and 0.3.…”

Section: Resultsmentioning

confidence: 99%

“…For example, Br ions dissolved in PbI 2 structures modify the interlayer interaction of the sandwiches, affecting the growth of PbI 2 in the c-direction [30,31]. Moreover, the addition of PbBr 2 above the solubility limit (approximately 5 mol.%) may produce mixtures of two phases, such as a β-solid solution (solid solution of ~5 mol.% PbBr 2 in PbI 2 matrix) with intermetallic compound PbBr 1.2 I 0.8 [32]. Therefore, the change in phases and morphological features of PbI 2 by the addition of PbBr 2 were investigated by X-ray diffraction (XRD) and scanning electron microscopy (SEM).…”

Section: Introductionmentioning

confidence: 99%

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Effects of the PbBr2:PbI2 Molar Ratio on the Formation of Lead Halide Thin Films, and the Ratio’s Application for High Performance and Wide Bandgap Solar Cells

et al. 2022

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We investigate the effects of the molar ratio (x) of PbBr2 on the phases, microstructure, surface morphology, optical properties, and structural defects of mixed lead halides PbI2(1−x)Br2x for use in solar cell devices. Results indicate that as x increased to 0.3, the surface morphology continued to improve, accompanied by the growth of PbI2 grains. This resulted in lead halide films with a very smooth and continuous morphology, including large grains when the film was formed at x = 0.3. In addition, the microstructure changed from (001)-oriented pure PbI2 to a highly (001)-oriented β (PbI2-rich) phase. The plausible mechanism for the enhanced morphology of the lead halide films by the addition of PbBr2 is proposed based on the growth of a Br-saturated lead iodide solid solution. Furthermore, iodine vacancies, identified by X-ray photoelectron spectroscopy, decreased as the ratio of PbBr2 increased. Finally, an electrical analysis of the solar cells was performed by using a PN heterojunction model, revealing that structural defects, such as iodine vacancies and grain boundaries, are the main contributors to the degradation of the performance of pure PbI2-based solar cells (including high leakage, low stability, and high hysteresis), which was significantly improved by the addition of PbBr2. The solar cell fabricated at x = 0.3 in air showed excellent stability and performance. The device lost merely 20% of the initial efficiency of 4.11% after 1500 h without encapsulation. This may be due to the dense microstructure and the reduced structural defects of lead halides formed at x = 0.3.

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Section: Resultssupporting

confidence: 83%

“…with the phases predicted by the phase diagram [32]. Very low intensities of the peaks of the two phases are observed, indicating that the phases are made of very fine particles.…”

Section: Resultsmentioning

confidence: 51%

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Effects of the PbBr2:PbI2 Molar Ratio on the Formation of Lead Halide Thin Films, and the Ratio’s Application for High Performance and Wide Bandgap Solar Cells

et al. 2022

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Structural Evolution of Sequentially Evaporated (Cs,FA)Pb(I,Br)₃ Perovskite Thin Films via In Situ X‐Ray Diffraction

Heinze,

Schulz,

Scheer

et al. 2024

Physica Status Solidi (a)

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Evaporation of perovskite thin films for solar cell applications is a solution‐free, well controllable and scalable deposition path with promising prospects for commercialization. This method yields homogeneous, smooth films while being able to compete with the best wet‐chemical solar cells. Compared to commonly applied simultaneous co‐evaporation of various halide precursor salts, sequential evaporation followed by an annealing step allows to better control the amount of deposited precursors, and has the potential to largely improve reproducibility. In this work, we deposit Cs/formamidinium (FA)‐based lead iodide perovskites via sequential evaporation in a vacuum chamber and investigate the phase formation and evolution of different precursor stacking sequences and annealing conditions with in situ X‐ray diagnostics. In addition, some Br is added in order to investigate the effect of halide intermixing. We find the precursor stacking sequence to strongly influence the formation of dominant phases in the case of different polytypes as well as the preferential orientation and morphology of as‐deposited films. These resulting layer properties in turn affect the diffusion conversion reaction during thermal annealing and ultimately the conversion ratio of the final perovskite layers. For example, we find that the stacking sequences with the A cations (CsI, FAI) as the first precursor layers favor fast and complete conversion of the perovskite phase. However, the result is the formation of perovskite layers with large voids.This article is protected by copyright. All rights reserved.

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Electronic band-structure and optical constants of Pb2GeS4: Ab initio calculations and X-ray spectroscopy experiments

Lavrentyev

Gabrelian

et al. 2018

J Mater Sci: Mater Electron

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Synthesis, electronic structure and optical properties of PbBr 1.2 I 0.8

Cited by 8 publications

References 26 publications

Effects of the PbBr2:PbI2 Molar Ratio on the Formation of Lead Halide Thin Films, and the Ratio’s Application for High Performance and Wide Bandgap Solar Cells

Effects of the PbBr2:PbI2 Molar Ratio on the Formation of Lead Halide Thin Films, and the Ratio’s Application for High Performance and Wide Bandgap Solar Cells

Structural Evolution of Sequentially Evaporated (Cs,FA)Pb(I,Br)₃ Perovskite Thin Films via In Situ X‐Ray Diffraction

Electronic band-structure and optical constants of Pb2GeS4: Ab initio calculations and X-ray spectroscopy experiments

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Synthesis, electronic structure and optical properties of PbBr 1.2 I 0.8

Cited by 8 publications

References 26 publications

Effects of the PbBr2:PbI2 Molar Ratio on the Formation of Lead Halide Thin Films, and the Ratio’s Application for High Performance and Wide Bandgap Solar Cells

Effects of the PbBr2:PbI2 Molar Ratio on the Formation of Lead Halide Thin Films, and the Ratio’s Application for High Performance and Wide Bandgap Solar Cells

Structural Evolution of Sequentially Evaporated (Cs,FA)Pb(I,Br)3 Perovskite Thin Films via In Situ X‐Ray Diffraction

Electronic band-structure and optical constants of Pb2GeS4: Ab initio calculations and X-ray spectroscopy experiments

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Structural Evolution of Sequentially Evaporated (Cs,FA)Pb(I,Br)₃ Perovskite Thin Films via In Situ X‐Ray Diffraction