Lead-Free Chiral Perovskite for High Degree of Circularly Polarized Light Emission and Spin Injection

Junchao Hu; Xinglin Wen; Dong Yang; Yingying Chen; Zeyi Liu; Dehui Li

doi:10.1021/acs.nanolett.3c04575

Lead-Free Chiral Perovskite for High Degree of Circularly Polarized Light Emission and Spin Injection

Nano Lett. 2024 Jan 24;24(3):1001-1008. doi: 10.1021/acs.nanolett.3c04575. Epub 2024 Jan 10.

Authors

Junchao Hu¹, Xinglin Wen^{1

2}, Dong Yang¹, Yingying Chen¹, Zeyi Liu¹, Dehui Li^{1

2}

Affiliations

¹ School of Optical and Electronic Information, Huazhong University of Science and Technology, Wuhan 430074, China.
² Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan 430074, China.

PMID: 38198561
DOI: 10.1021/acs.nanolett.3c04575

Abstract

We report a zero-dimensional (0D) lead-free chiral perovskite (S-/R-MBA)₄Bi₂I₁₀ with a high degree of circularly polarized light (CPL) emission. Our 0D lead-free chiral perovskite exhibits an average degree of circular polarization (DOCP) of 19.8% at 78 K under linearly polarized laser excitation, and the maximum DOCP can reach 25.8%, which is 40 times higher than the highest DOCP of 0.5% in all reported lead-free chiral perovskites to the best of our knowledge. The high DOCP of (S-/R-MBA)₄Bi₂I₁₀ is attributed to the free exciton emission with a Huang-Rhys factor of 2.8. In contrast, all the lead-free chiral perovskites in prior reports are dominant by self-trapped exciton in which the spin relaxation reduces DOCP dramatically. Moreover, we realize the manipulation of the valley degree of freedom of monolayer WSe₂ by using the spin injection of the 0D chiral lead-free perovskites. Our results provide a new perspective to develop lead-free chiral perovskite devices for CPL light source, spintronics, and valleytronics.

Keywords: 0D chiral perovskites; circularly polarized light; lead-free; spin-injection; valley.