Dynamic symmetry breaking and spin splitting in metal halide perovskites

Scott McKechnie; Jarvist M. Frost; Dimitar Pashov; Pooya Azarhoosh; Aron Walsh; Mark van Schilfgaarde

doi:10.1103/physrevb.98.085108

Control of Crystal Symmetry Breaking with Halogen-Substituted Benzylammonium in Layered Hybrid Metal-Halide Perovskites

Journal of the American Chemical Society ◽

10.1021/jacs.9b11809 ◽

2020 ◽

Vol 142 (11) ◽

pp. 5060-5067 ◽

Cited By ~ 9

Author(s):

Tanja Schmitt ◽

Sean Bourelle ◽

Nathaniel Tye ◽

Giancarlo Soavi ◽

Andrew D. Bond ◽

...

Keyword(s):

Symmetry Breaking ◽

Metal Halide ◽

Crystal Symmetry ◽

Halide Perovskites

Download Full-text

Structural descriptor for enhanced spin-splitting in 2D hybrid perovskites

Nature Communications ◽

10.1038/s41467-021-25149-7 ◽

2021 ◽

Vol 12 (1) ◽

Cited By ~ 1

Author(s):

Manoj K. Jana ◽

Ruyi Song ◽

Yi Xie ◽

Rundong Zhao ◽

Peter C. Sercel ◽

...

Keyword(s):

Degrees Of Freedom ◽

Metal Halide ◽

Spin Splitting ◽

Potential Candidate ◽

Global Space ◽

Structural Descriptor ◽

Broad Array ◽

Local Inversion ◽

Halide Perovskites ◽

Strong Spin

AbstractTwo-dimensional (2D) hybrid metal halide perovskites have emerged as outstanding optoelectronic materials and are potential hosts of Rashba/Dresselhaus spin-splitting for spin-selective transport and spin-orbitronics. However, a quantitative microscopic understanding of what controls the spin-splitting magnitude is generally lacking. Through crystallographic and first-principles studies on a broad array of chiral and achiral 2D perovskites, we demonstrate that a specific bond angle disparity connected with asymmetric tilting distortions of the metal halide octahedra breaks local inversion symmetry and strongly correlates with computed spin-splitting. This distortion metric can serve as a crystallographic descriptor for rapid discovery of potential candidate materials with strong spin-splitting. Our work establishes that, rather than the global space group, local inorganic layer distortions induced via appropriate organic cations provide a key design objective to achieve strong spin-splitting in perovskites. New chiral perovskites reported here couple a sizeable spin-splitting with chiral degrees of freedom and offer a unique paradigm of potential interest for spintronics.

Download Full-text

Structural descriptor for enhanced spin-splitting in 2D hybrid perovskites

10.21203/rs.3.rs-472412/v1 ◽

2021 ◽

Author(s):

Manoj Jana ◽

Ruyi Song ◽

Yi Xie ◽

Rundong Zhao ◽

Peter Sercel ◽

...

Keyword(s):

Degrees Of Freedom ◽

Metal Halide ◽

Spin Splitting ◽

Potential Candidate ◽

Global Space ◽

Structural Descriptor ◽

Broad Array ◽

Local Inversion ◽

Halide Perovskites ◽

Strong Spin

Abstract Two-dimensional (2D) hybrid metal halide perovskites have emerged as outstanding optoelectronic materials and are potential hosts of Rashba/Dresselhaus spin-splitting for spin-selective transport and spin-orbitronics. However, a quantitative microscopic understanding of what controls the spin-splitting magnitude is generally lacking. Through crystallographic and first-principles studies on a broad array of chiral and achiral 2D perovskites, we demonstrate that a specific bond angle disparity connected with asymmetric tilting distortions of metal halide octahedra breaks local inversion symmetry and strongly correlates with computed spin-splitting. This distortion metric can serve as a crystallographic descriptor for rapid discovery of potential candidate materials with strong spin-splitting. Our work establishes that rather than global space group, local inorganic layer distortions induced via appropriate organic cations provide a key design principle to achieve strong spin-splitting in perovskites. New chiral perovskites reported here couple a sizeable spin-splitting with chiral degrees of freedom and offer a unique paradigm of potential interest for spintronics.

Download Full-text

Lead-Free Metal Halide Perovskite Nanocrystals for Photocatalysis in Water

10.26434/chemrxiv.9794270 ◽

2019 ◽

Author(s):

Subhajit Bhattacharjee ◽

Sonu Pratap Chaudhary ◽

Sayan Bhattacharyya

Keyword(s):

Charge Carrier ◽

Wide Spectrum ◽

Real Life ◽

Metal Halide ◽

Lead Free ◽

Water Medium ◽

Type I ◽

Type Ii ◽

Perovskite Layer ◽

Halide Perovskites

Metal halide perovskites with high absorption coefficient, direct generation of free charge carriers, excellent ambipolar charge carrier transport properties, point-defect tolerance, compositional versatility and solution processability are potentially transforming the photovoltaics and optoelectronics industries. However their limited ambient stability, particularly those of iodide perovskites, obscures their use as photocatalysts especially in aqueous medium. In an unprecedented approach we have exploited the photo-absorption property of the less toxic lead-free Cs3Bi2X9 (X = Br, I) nanocrystals (NCs) to catalyse the degradation of water pollutant organic dye, methylene blue (MB) in presence of visible light at room temperature. After providing a proof-of-concept with bromide perovskites in isopropanol, the perovskites are employed as photocatalysts in water medium by designing perovskite/Ag2S and perovskite/TiO2 composite systems, with Type I (or quasi Type II) and Type II alignments, respectively. Ag2S and TiO2 coatings decelerate penetration of water into the perovskite layer while facilitating charge carrier extraction. With a minimal NC loading, Cs3Bi2I9/Ag2S degrades ~90% MB within an hour. Our approach has the potential to unravel the photocatalytic properties of metal halide perovskites for a wide spectrum of real-life applications.

Download Full-text