A hybrid organic-inorganic perovskite dataset

Kim, Chiho; Krishnan, Sridevi; Ramprasad, Rampi

doi:10.1038/sdata.2017.57

Cited by 142 publications

(146 citation statements)

References 87 publications

Supporting

Mentioning

139

Contrasting

Unclassified

Order By: Relevance

“…Including 16 organic cations (see Figure 2 for a list of monovalent cations) in their work, Kim et al [139] investigate the compounds resulting from permutations of group XIV elements (Ge, Sn, and Pb) with halides (F, Cl, Br, and I). Note that all structural motives are archived, i.e., including ABX 3 compounds that are structurally are no HPs.…”

Section: Organic A-site: Hp(a)mentioning

confidence: 99%

“…[116] Albeit using the inorganic Cs + on the A-site, the structural similarities between Cs and MA perovskites justifies drawing some insight from this study. [116,139] Among the alkaline-earth metals, Be 2+ appears too small (t > 1 for Cs + or MA + (using 2.17 Å) halides X =Cl, Br, and I). Even some examples with band gaps predicted to fall in an interesting range at least for tandem PV applications were found.…”

Section: Organic A-site: Hp(a)mentioning

confidence: 99%

“…[20] In order to replace a +2 B-site ion, elements with stable OS = +1 and +3 are most suitable, such as group XI (Cu, Ag, and Au), group X (mainly Pd), and group XIII (mainly Tl) elements. [157] Computational screening of such Cs 2 BB′X 6 structure (B′ = Sb and Bi; B = Cu, Ag, and Au) has been carried out by Volonakis et al [158] and finally including organic A-site molecules by Kim et al, [139] after this concept was first employed for HPs for (MA) 2 Tl + Bi 3+ I 6 . [155] Of course, this concept is not just limited to a single elemental species, but can also be used to mix elements in order to employ other OS (although in such a case, the term disproportionation is technically incorrect).…”

Section: Organic A-site: Hp(a)mentioning

confidence: 99%

See 2 more Smart Citations

Mix and Match: Organic and Inorganic Ions in the Perovskite Lattice

Gebhardt

Rappe

2018

Advanced Materials

View full text Add to dashboard Cite

X-site anions are possible, with only two general requirements that must be fulfilled: i) charge neutrality in the ABX 3 unit (typically, X is a divalent or monovalent anion, hence A and B cations with oxidation states between +1 and +5 can be combined) and ii) the ionic radii of the chosen composition must allow the above coordination, or different phases become more stable. Both of these simple design rules have a certain flexibility.The electronic argument i) can be stretched by allowing the combination of multiple ABX 3 units to form an overall charge neutral unit. For example, this is the case when considering A 2 BB′X 6 or AA′B 2 X 6 systems. Such double perovskite systems are known with B and B′ (A and A′) being the same elemental species (disproportion in oxidation state, e.g., Cs 2 Au + Au 3+ I 6 ) [20] or different ones (e.g., SrBaTi 2 O 6 [21] and SrPbTi 2 O 6 [22] for A-site disproportion or K 2 NbTaO 6 [23] and Bi 2 FeCrO 6 [24] for the B-site). Of course, this concept can also be used to combine three ABX 3 units (e.g., (CaTiO 3 ) n (SrTiO 3 ) l (BaTiO 3 ) m [25-27]) and much more complex stoichiometries with mixed ratios (e.g., (Pb 2 InNbO 6 ) 3/4 (Ba 2 InBiO 6 ) 1/4 [28] or [CaMn 3 3+ ][Mn 3 3+ Mn 4+ ] O 12 ] [29] ). Furthermore, although the bonding character in oxide perovskites is often mainly ionic, some compositions have an increased level of covalency (e.g., halides, sulfides, Bi-and Pbbased oxide perovskites). Thus, the electronic shell configuration and other effects like the steric demands of a metal lonepair will influence the structure and stability of ABX 3 perovskite compounds.In addition, the geometric argument ii) allows for some flexibility. For a perfectly cubic perovskite, the (effective) ionic radii r must fulfill the relation of Goldschmidt's tolerance factor 2( ) 1 A X B X t r r r r = + + = . [30,31] However, perovskites can exist also with t being not ideal, usually in a range of about 0.75 < t < 1.05. [8] Whenever t ≠ 1, the crystal distorts from an ideal cubic lattice, usually in form of off-center displacements, octahedral rotations, or a combination of both. The classification of Glazer [32,33] can be used to describe such distortions from a perfectly cubic perovskite. [34] It is further possible that ABX 3 compounds are stable whose t does not fall into the interval that is required for the perovskite crystal structure. In these cases that are no longer stabilized by deformations and tilting, one observes other phases where the connectivity of BX 6Materials science evolves to a state where the composition and structure of a crystal can be controlled almost at will. Given that a composition meets basic requirements of stoichiometry, steric demands, and charge neutrality, researchers are now able to investigate a wide range of compounds theoretically and, under various experimental conditions, select the constituting fragments of a crystal. One intriguing playground for such materials design is the perovskite structure. While a game of mixing and matching ions has been pla...

show abstract

Section: Organic A-site: Hp(a)mentioning

confidence: 99%

Section: Organic A-site: Hp(a)mentioning

confidence: 99%

Section: Organic A-site: Hp(a)mentioning

confidence: 99%

See 1 more Smart Citation

Mix and Match: Organic and Inorganic Ions in the Perovskite Lattice

Gebhardt

Rappe

2018

Advanced Materials

View full text Add to dashboard Cite

show abstract

“…[26][27][28][29][30][31][32][33] Except for the aforementioned computational cost, first-principles-based methods for computing atomic forces are considered to meet these requirements. Our reference data was prepared using a two-step procedure.…”

Section: Strategymentioning

confidence: 99%

A universal strategy for the creation of machine learning-based atomistic force fields

et al. 2017

Self Cite

View full text Add to dashboard Cite

Emerging machine learning (ML)-based approaches provide powerful and novel tools to study a variety of physical and chemical problems. In this contribution, we outline a universal strategy to create ML-based atomistic force fields, which can be used to perform high-fidelity molecular dynamics simulations. This scheme involves (1) preparing a big reference dataset of atomic environments and forces with sufficiently low noise, e.g., using density functional theory or higher-level methods, (2) utilizing a generalizable class of structural fingerprints for representing atomic environments, (3) optimally selecting diverse and non-redundant training datasets from the reference data, and (4) proposing various learning approaches to predict atomic forces directly (and rapidly) from atomic configurations. From the atomistic forces, accurate potential energies can then be obtained by appropriate integration along a reaction coordinate or along a molecular dynamics trajectory. Based on this strategy, we have created model ML force fields for six elemental bulk solids, including Al, Cu, Ti, W, Si, and C, and show that all of them can reach chemical accuracy. The proposed procedure is general and universal, in that it can potentially be used to generate ML force fields for any material using the same unified workflow with little human intervention. Moreover, the force fields can be systematically improved by adding new training data progressively to represent atomic environments not encountered previously.

show abstract

“…Organic–inorganic hybrid perovskites (OIHPs) have gained unprecedented attention due to their high power conversion efficiencies (PCE) for solar cell applications . The prototypical halide perovskite semiconductor methylammonium lead iodide chloride (CH 3 NH 3 PbI 3− x Cl x ) is by far one of the most successful photovoltaic candidates for achieving championed PCE because of its direct–indirect bandgap with optimalgap energy (≈1.5 eV), low binding energy for efficient exciton dissociation, high absorption coefficient within the wide solar spectrum, and long electronic charge transport distance (≈1−10 µm) . In fact, its octahedral crystalline framework together with the randomly oriented and caged organic constituent (i.e., CH 3 NH 3 + ) is expected to offer semiconducting, ferroelectric, and even spin‐related characteristics simultaneously .…”

mentioning

confidence: 99%