Intrinsic Halide Immiscibility in 2D Mixed-Halide Ruddlesden–Popper Perovskites

Roy, Chris R.; Zhou, Yadong; Kohler, Daniel D.; Zhu, Zihua; Wright, John; Jin, Song

doi:10.1021/acsenergylett.2c01631

Cited by 15 publications

(22 citation statements)

References 55 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Homologous n series of RP perovskites have been shown to have type-I band alignment, which induces carrier funneling and photon recycling from low to high n phases in phase-impure RP perovskite mixtures. , This effect likely explains why the PL spectra imply a pure or majority high n phase, in contradiction to the absorbance spectra. These results attest to the superior accuracy and sensitivity of absorbance in the spectroscopic determination of the compositions of mixed phase RP perovskite samples . The n > 3 nanosheets were usually mixed n to some degree, as shown in a survey of the comparative PL and absorption spectra for four n = 4 nanosheets in Figure S6.…”

mentioning

confidence: 59%

“…These results attest to the superior accuracy and sensitivity of absorbance in the spectroscopic determination of the compositions of mixed phase RP perovskite samples. 39 The n > 3 nanosheets were usually mixed n to some degree, as shown in a survey of the comparative PL and absorption spectra for four n = 4 nanosheets in Figure S6. However, we are confident in our assignment of the absorption and emission energies for n > 3 phases due to reproducible synthesis of nanosheets with consistent absorption and emission peaks.…”

mentioning

confidence: 94%

See 1 more Smart Citation

High Layer Number (n = 1–6) 2D Ruddlesden–Popper Lead Bromide Perovskites: Nanosheets, Crystal Structure, and Optoelectronic Properties

Forlano,

Roy,

Mihalyi-Koch

et al. 2023

ACS Materials Lett.

Self Cite

View full text Add to dashboard Cite

2D Ruddlesden−Popper (RP) lead halide perovskites have highly tunable structures, compositions, and properties that enable their promising optoelectronic applications. Among various 2D halide perovskites, the materials chemistry and fundamental optoelectronic properties of high layer number (n) lead-bromide RP perovskites, where n refers to the number of inorganic octahedra layers, have been less studied. Here, we report the synthesis of thin nanosheets of (PEA) 2 Cs n−1 Pb n Br 3n+1 (n = 1−6, PEA = phenylethylammonium) perovskites and study the optical properties, assigning photoluminescence emissions of 486, 496, and 505 nm to n = 4−6 phases, respectively, and reporting the photoluminescence lifetimes. The crystal structure of (PEA) 2 Cs 2 Pb 3 Br 10 was determined to reveal minimal octahedral structural distortions. Ultraviolet photoelectron spectroscopy measurements reveal the positioning of the valence and conduction bands for n = 1−3 phases and confirm the type-I band alignment for the (PEA) 2 Cs n−1 Pb n Br 3n+1 series, laying the foundation for rational heterostructure device design in the future.

show abstract

mentioning

confidence: 59%

mentioning

confidence: 94%

High Layer Number (n = 1–6) 2D Ruddlesden–Popper Lead Bromide Perovskites: Nanosheets, Crystal Structure, and Optoelectronic Properties

Forlano,

Roy,

Mihalyi-Koch

et al. 2023

ACS Materials Lett.

Self Cite

View full text Add to dashboard Cite

show abstract

“…Further, as the authors have also mentioned, the synthesis technique used would also dictate the extent of halide ion immiscibility. 72 In any case, it is clear that 2D perovskites, just like 3D perovskites, are prone to undergo halide ion segregation.…”

Section: Intrinsic Halide Ion Segregationmentioning

confidence: 99%

Ramifications of Ion Migration in 2D Lead Halide Perovskites

Mathew,

Cho,

Kamat

2024

ACS Energy Lett.

View full text Add to dashboard Cite

Lower dimensional or 2D halide perovskites, with their versatile structural and functional properties, are known to improve the performance and room temperature stability of perovskite solar cells. One would expect 2D perovskites to be more resistant to ion migration compared to their 3D counterparts because of the presence of bulky organic cations. However, recent findings show that ion migration indeed is prevalent in 2D halide perovskites similar to 3D perovskites. Halide ion migration in 2D perovskites manifests itself in halide ion segregation under photoirradiation as well as in halide exchange between physically paired films of 2D perovskites with different halide ions. Besides halide ion migration, cation migration of spacer cations and A-site cations is also seen when 2D/3D perovskite films are subjected to light and thermal stress. It is important to recognize the importance of ion migration while incorporating 2D perovskites in solar cells and other optoelectronic devices, as it can be detrimental for achieving streamlined performance and long-term stability. This Perspective discusses recent reports on ion migration in 2D and in 2D/3D halide perovskite films under the operational conditions (at elevated temperature and given built-in bias) and presents a few mitigating strategies.

show abstract

“…The RP perovskite materials considered here have the formula: BA 2 MA n –1 Pb n I 3 n +1 , where BA is the spacer cation and MA is methylammonium, the “A” site cation residing in the cavities in the octahedral layers. Many other compositions are possible, including other spacer cations, A cations, − and mixed halide compositions, , all of which will affect the optoelectronic properties. Quantum confinement of charge carriers in the octahedral layers leads to several phenomena including stable excitons at room temperature .…”

Section: Introductionmentioning

confidence: 99%

Spatial Heterogeneity of Biexcitons in Two-Dimensional Ruddlesden–Popper Lead Iodide Perovskites

et al. 2023

Self Cite

View full text Add to dashboard Cite

Quantum confinement in two-dimensional (2D) Ruddlesden−Popper (RP) perovskites leads to the formation of stable quasi-particles, including excitons and biexcitons, the latter of which may enable lasing in these materials. Due to their hybrid organic−inorganic structures and the solution phase synthesis, microcrystals of 2D RP perovskites can be quite heterogeneous, with variations in excitonic and biexcitonic properties between crystals from the same synthesis and even within individual crystals.Here, we employ one-and two-quantum two-dimensional whitelight microscopy to systematically study the spatial variations of excitons and biexcitons in microcrystals of a series of 2D RP perovskites BA 2 MA n−1 Pb n I 3n+1 (n = 2−4, BA= butylammonium, MA = methylammonium). We find that the average biexciton binding energy of around 60 meV is essentially independent of the perovskite layer thickness (n). We also resolve spatial variations of the exciton and biexciton energies on micron length scales within individual crystals. By comparing the one-quantum and twoquantum spectra at each pixel, we conclude that biexcitons are more sensitive to their environments than excitons. These results shed new light on the ways disorder can modify the energetic landscape of excitons and biexcitons in RP perovskites and how biexcitons can be used as a sensitive probe of the microscopic environment of a semiconductor.

show abstract

Intrinsic Halide Immiscibility in 2D Mixed-Halide Ruddlesden–Popper Perovskites

Cited by 15 publications

References 55 publications

High Layer Number (n = 1–6) 2D Ruddlesden–Popper Lead Bromide Perovskites: Nanosheets, Crystal Structure, and Optoelectronic Properties

High Layer Number (n = 1–6) 2D Ruddlesden–Popper Lead Bromide Perovskites: Nanosheets, Crystal Structure, and Optoelectronic Properties

Ramifications of Ion Migration in 2D Lead Halide Perovskites

Spatial Heterogeneity of Biexcitons in Two-Dimensional Ruddlesden–Popper Lead Iodide Perovskites

Contact Info

Product

Resources

About