Interfacial α-FAPbI3 phase stabilization by reducing oxygen vacancies in SnO2−x

Lee, Jung Hwan; Lee, Sunje; Kim, Tae-Hee; Ahn, Hyungju; Jang, Gyu Yong; Kim, Kwang Hee; Cho, Yoon Jun; Zhang, Kan; Park, Ji-Sang; Park, Jae Hyung

doi:10.1016/j.joule.2022.12.006

Cited by 41 publications

(30 citation statements)

References 28 publications

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“…The TiCl 4 was selected because Cl À anion is well known as a good candidate to increase perovskite grains while Ti 4 + cation is expected to beneficial for decreasing oxygen vacancies due to less multivalency in contrast to Sn 4 + . [48][49][50] First-principles density functional theory (DFT) calculation was performed to determine the adsorption energy (E ads ) of the hydroxyl oxygen on the SnO 2 (110) surface (Figure 1a) [51] and the formation energy (E f ) of oxygen vacancies (Figure 1b). The determined values were shown in Figure 1c.…”

Section: Defects Regulation For Flexible Sno 2 Layermentioning

confidence: 99%

Interfacial Engineering for Efficient Low‐Temperature Flexible Perovskite Solar Cells

Cai,

Yang,

Liu

et al. 2023

Angew Chem Int Ed

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Photovoltaic technology with low weight, high specific power in cold environments, and compatibility with flexible fabrication is highly desired for near‐space vehicles and polar region applications. Herein, we demonstrate efficient low‐temperature flexible perovskite solar cells by improving the interfacial contact between electron‐transport layer (ETL) and perovskite layer. We find that the adsorbed oxygen active sites and oxygen vacancies of flexible tin oxide (SnO2) ETL layer can be effectively decreased by incorporating a trace amount of titanium tetrachloride (TiCl4). The effective defects elimination at the interfacial increases the electron mobility of flexible SnO2 layer, regulates band alignment at the perovskite/SnO2 interface, induces larger perovskite crystal growth, and improves charge collection efficiency in a complete solar cell. Correspondingly, the improved interfacial contact transforms into high‐performance solar cells under one‐sun illumination (AM 1.5G) with efficiencies up to 23.7% at 218 K, which might open up a new era of application of this emerging flexible photovoltaic technology to low‐temperature environments such as near‐space and polar regions.

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Section: Defects Regulation For Flexible Sno 2 Layermentioning

confidence: 99%

Interfacial Engineering for Efficient Low‐Temperature Flexible Perovskite Solar Cells

Cai,

Yang,

Liu

et al. 2023

Angew Chem Int Ed

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“…Common metal elements for solid catalysts included Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd, La, Hf, Ta, W, Re, Os, Ir, Pt, and so forth. However, only a part of metal elements can be selected to form a single-phase HEO, where the atomic radius and crystal field coordination behavior play a major role. − According to the law of metal selection for HEOs, Fe and Zn were adjusted, while the introduction of other metal elements such as Cr, Mo, or Ti can cause impurity phases. The influence of changing Fe or Zn in HEOs was not significant on E ov ( E ov/(MnCuCo8NiFe) x O y = 2.36 eV, E ov/(MnCuCo8NiZn) x O y = 2.47 eV, E ov/(MnCuCo3NiZn) x O y = 2.54 eV, E ov/(MnCuCo3NiFe) x O y = 2.28 eV, and E ov/(MnCuCoNiFe) x O y = 2.41 eV), as shown in Scheme .…”

Section: Resultsmentioning

confidence: 99%

“…The O 1s spectra of the catalysts showed two peaks: (i) lattice oxygen (O α ) at ∼529.9 eV and (ii) O component associated with the O 2– ions in surface oxygen vacancies (O β ) at ∼531.5 eV. Therefore, the concentration of surface oxygen vacancies of the catalysts can be estimated by the integrated peak areas using the following equation: Oxygen 0.25em vacancy 0.25em concentration = normalO β normalO α ∗ 100 % …”

Section: Resultsmentioning

confidence: 99%

Tuning Oxygen Vacancies in Oxides by Configurational Entropy

Zhang,

Duan,

Gao

et al. 2023

ACS Appl. Mater. Interfaces

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Tuning surface oxygen vacancies is important for oxide catalysts. Doping elements with different chemical valence states or different atomic radii into host oxides is a common method to create oxygen vacancies. However, the concentration of oxygen vacancies in oxide catalysts is still limited to the amount of foreign dopants that can be tolerated (generally less than 10% atoms). Herein, a principle of engineering the configurational entropy to tune oxygen vacancies was proposed. First, the positive relationship between the configuration entropy and the formation energy of oxygen vacancies (E ov) in 16 model oxides was estimated by a DFT calculation. To verify this, single binary oxides and high-entropy quinary oxides (HEOs) were prepared. Indeed, the concentration of oxygen vacancies in HEOs (Oβ/α = 3.66) was higher compared to those of single or binary oxides (Oβ/α = 0.22–0.75) by O1s XPS, O2-TPD, and EPR. Interestingly, the reduction temperatures of transition metal ions in HEOs were generally lower than that in single-metal oxides by H2-TPR. The lower E ov of HEOs may contribute to this feature, which was confirmed by in situ XPS and in situ XRD. Moreover, with catalytic CO/C3H6 oxidation as a model, the high-entropy (MnCuCo3NiFe) x O y catalyst showed higher catalytic activity than single and binary oxides, which experimentally verified the hypothesis of the DFT calculation. This work may inspire more oxide catalysts with preferred oxygen vacancies.

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“…Meanwhile, the polarity of the –C 6 H 5 O 7 group can enhance itself to react with the perovskite via hydrogen bonds, which can facilitate heterogeneous nucleation over the perovskite precursor film or modulate the orientation or distribution of organic cation groups, stabilizing the α-phase of FAPbI 3 at this interface. 49 Moreover, the polar molecule group could react with SnO 2 to reduce the oxygen vacancies, which decreases the nonradiative recombination for the uniformity of SnO 2 films. These are beneficial for improving the ETL interfacial contact with the perovskite, forming more electron-transferring channels, resulting in the appearance with a smaller τ 2 than that of the pristine perovskite.…”

Section: Resultsmentioning

confidence: 99%

“…Thus, more oxygen anions could be easily ionized to slightly increase the alkalinity of the corresponding solution, which is favorable to improve the perovskite morphology and enhance the stabilities of the PSCs. 46–48 Since the interface contains a higher proportion of structural defects than the bulk, 49 here, potassium citrate (C 6 H 5 K 3 O 7 ) is employed to modify the perovskite/SnO 2 QD interface. The non-toxic and eco-friendly interfacial layer can improve the short-circuit current ( J SC ), open-circuit voltage ( V OC ), and fill factor (FF), and the corresponding champion device delivered a high PCE of 24.12% and a high FF of 82.1% with the improved air stability.…”

Section: Introductionmentioning

confidence: 99%