Regulatory tolerance and octahedral factors by using vacancy in APbI3 perovskites

Ji, Denghui; Feng, Shunzhen; Wang, Li; Wang, Shuling; Na, Mula; Hong, Zhigang; Zhang, Congmin; Li, Xiuling

doi:10.1016/j.vacuum.2019.03.018

Cited by 48 publications

(23 citation statements)

References 41 publications

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“…While the representative EDX spectra of the samples have been placed in Figure S4, the respective average atomic % of the constituent elements has been appended in Table . The results for Cs 2 NaBiI 6 showed the achievement of a homogeneous composition of the elements in the double perovskite, as well as a stoichiometry comparable to the previous report . In this material, the compositional analysis indicated the incorporation of sodium in Cs 3 Bi 2 I 9 after doping and is in agreement with the XRD results.…”

Section: Resultssupporting

confidence: 89%

“…The results for Cs 2 NaBiI 6 showed the achievement of a homogeneous composition of the elements in the double perovskite, as well as a stoichiometry comparable to the previous report. 35 In this material, the compositional analysis indicated the incorporation of sodium in Cs 3 Bi 2 I 9 after doping and is in agreement with the XRD results. On the other hand, in the Cs 3 Bi 2 I 9 •xNa 2 S thin films with varying Na 2 S contents, such analysis showed an increasing sodium content with an increase in the doping concentration.…”

Section: ■ Results and Discussionsupporting

confidence: 86%

“…For the alloys, we used a weighted average of the effective ionic radii of Bi 3+ and Na + at the B-sites and, since sulfur ions reside at the interstitial sites, we have not considered their influence in regard to estimating the factors (t and μ). 35 The values, as presented in Table 1, turned out to be within the range required to form a stable perovskite (t = 0.80−1.0 and μ > 0.44). The estimated values for Cs 2 NaBiI 6 , moreover, were similar to those for the archetypal MAPI perovskite, indicating the formation of a three-dimensional structure.…”

Section: ■ Results and Discussionmentioning

confidence: 75%

“…Due to a paucity of reports on Cs 2 NaBiI 6 developed through a solution-based approach, we first followed a conventional practice in order to estimate the tolerance factors ( t ) and octahedral factors (μ) of the pristine and Na 2 S-incorporated Cs 3 Bi 2 I 9 perovskites and the Cs 2 NaBiI 6 double perovskite formed through a direct approach. For the alloys, we used a weighted average of the effective ionic radii of Bi 3+ and Na + at the B -sites and, since sulfur ions reside at the interstitial sites, we have not considered their influence in regard to estimating the factors ( t and μ) . The values, as presented in Table , turned out to be within the range required to form a stable perovskite ( t = 0.80–1.0 and μ > 0.44).…”

Section: Resultsmentioning

confidence: 99%

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Bandgap Engineering and Efficient Conversion of a Ternary Perovskite (Cs₃Bi₂I₉) to a Double Perovskite (Cs₂NaBiI₆) with the Aid of Alkali Metal Sulfide

2020

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The success of iodobismuth ternary perovskites, such as Cs 3 Bi 2 I 9 , in solar cell applications has so far been limited due to their wide bandgaps and low structural dimensionalities. In order to address these prevailing issues, we report the bifunctional role of an alkali metal sulfide (Na 2 S) treatment on the Cs 3 Bi 2 I 9 perovskite. We found that the incorporation of Na 2 S in such a zero-dimensional Cs 3 Bi 2 I 9 structure not only lowers its optical bandgap but also leads to an efficient conversion to a threedimensional Cs 2 NaBiI 6 double perovskite structure with a closer-to-optimal bandgap for solar energy conversion. The structural characterization and optical properties of Cs 3 Bi 2 I 9 with a varying contents of Na 2 S show that each monovalent sodium cation replaces a trivalent bismuth ion in the Cs 3 Bi 2 I 9 structure and enforces its transformation to a double perovskite framework (Cs 2 NaBiI 6 ); the divalent sulfur ions occupy the interstitial sites and in turn tune the optical bandgap. The conduction and valence band energies, and hence the transport gap, of this series of materials have been estimated from scanning tunneling spectroscopy studies and the density of states spectra obtained thereof. The evolution of the band edges following the incorporation of Na 2 S has been explained by considering the contributions of the atomic orbitals. As evidenced from atomic force microscopy studies, such metal sulfide-aided conversion also leads to a superior surface morphology in the converted double perovskites. This work hence demonstrates an effective process for converting a large bandgap lowdimensional ternary perovskite to a low-bandgap three-dimensional double perovskite.

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Section: Resultssupporting

confidence: 89%

Section: ■ Results and Discussionsupporting

confidence: 86%

Section: ■ Results and Discussionmentioning

confidence: 75%

Section: Resultsmentioning

confidence: 99%

See 2 more Smart Citations

Bandgap Engineering and Efficient Conversion of a Ternary Perovskite (Cs₃Bi₂I₉) to a Double Perovskite (Cs₂NaBiI₆) with the Aid of Alkali Metal Sulfide

2020

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“…The highest C value (5.2 Â 10 5 K) was measured for the 23% La sample ( Table 1). The C value is related to the grain size and porosity of the samples [35]. The…”

Section: Dielectric Properties Of Plt Nanoparticlesmentioning

confidence: 99%

Ferroelectric behavior and spectroscopic properties of La-Modified lead titanate nanoparticles prepared by a sol-gel method

Mostafa

Alrowaili

Rashwan

et al. 2020

Heliyon

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A B S T R A C TThe sol-gel method was used to prepare perovskite type (Pb 1-1.5x La x □ 0.5x )TiO 3 (PLT) ceramics with x ¼ 0.21, 0.22, 0.23, 0.24, 0.25 in order to investigate their structural, optical, and dielectric properties. The crystallite compounds were obtained by calcinating the mixture of PbCO 3 , TiO 2 , and La 2 O 3 at 1000 C for different time periods. After 4 h annealing, PLT23 sample, approximately a very little secondary phases have been observed in the XRD spectrum of the PLT sample with 23% La content (PLT23). The presence of La dopants might have affected the tetragonality of the Lead titanate crystal structure. The PLT samples tolerance factor decreases from 0.991 as in x ¼ 0.21 to 0.986 for x ¼ 0.25. Hence, these structures tend, generally, to be in the perovskite phase as t~1. In the doped ceramics, characteristic phase transitions were shifted to lower temperatures. The dielectric permittivity value showed the tendency of a slight increase with lanthanum addition and achieved its maximum ε m (3649) at x ¼ 0.23, then it decreases for higher concentrations of La. The samples' estimated average crystallite size ranged from 40 nm to 50 nm, the maximum crystallite size about (49.6 nm) at x ¼ 0.23 La. The calculated bandgaps were 3.1, 3.26, 3.28, 3.08, and 3.12 for the PLT with 0.21, 0.22, 0.23,0.24 and 0.25% La, respectively.The Curie constant C was obtained as the slope of the curve of the inverse values of ε r vs. temperature. The highest C value (5.2 Â 10 5 K) was measured for the 23% La sample. The sample with 23% La content appears to be notably distinguished in its structural, optical, and dielectric characteristics compared with other samples.

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Chemical Processing of Mixed‐Cation Hybrid Perovskites: Stabilizing Effects of Configurational Entropy

Ünlü

Jung

Öz

et al. 2021

Perovskite Solar Cells

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Regulatory tolerance and octahedral factors by using vacancy in APbI3 perovskites

Cited by 48 publications

References 41 publications

Bandgap Engineering and Efficient Conversion of a Ternary Perovskite (Cs₃Bi₂I₉) to a Double Perovskite (Cs₂NaBiI₆) with the Aid of Alkali Metal Sulfide

Bandgap Engineering and Efficient Conversion of a Ternary Perovskite (Cs₃Bi₂I₉) to a Double Perovskite (Cs₂NaBiI₆) with the Aid of Alkali Metal Sulfide

Ferroelectric behavior and spectroscopic properties of La-Modified lead titanate nanoparticles prepared by a sol-gel method

Chemical Processing of Mixed‐Cation Hybrid Perovskites: Stabilizing Effects of Configurational Entropy

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Regulatory tolerance and octahedral factors by using vacancy in APbI3 perovskites

Cited by 48 publications

References 41 publications

Bandgap Engineering and Efficient Conversion of a Ternary Perovskite (Cs3Bi2I9) to a Double Perovskite (Cs2NaBiI6) with the Aid of Alkali Metal Sulfide

Bandgap Engineering and Efficient Conversion of a Ternary Perovskite (Cs3Bi2I9) to a Double Perovskite (Cs2NaBiI6) with the Aid of Alkali Metal Sulfide

Ferroelectric behavior and spectroscopic properties of La-Modified lead titanate nanoparticles prepared by a sol-gel method

Chemical Processing of Mixed‐Cation Hybrid Perovskites: Stabilizing Effects of Configurational Entropy

Contact Info

Product

Resources

About

Bandgap Engineering and Efficient Conversion of a Ternary Perovskite (Cs₃Bi₂I₉) to a Double Perovskite (Cs₂NaBiI₆) with the Aid of Alkali Metal Sulfide

Bandgap Engineering and Efficient Conversion of a Ternary Perovskite (Cs₃Bi₂I₉) to a Double Perovskite (Cs₂NaBiI₆) with the Aid of Alkali Metal Sulfide