Time-resolved Photoluminescence measurements in low dimensional magnetic semiconductor: CrSBr*

In the field of opto-spintronics, CrSBr is a particularly promising magnetic semiconductor due to its high conductivity, direct bandgap, high Neel temperature, and optically active defects^1,2. At temperatures below ~ 140 K, ultrathin CrSBr becomes a type A antiferromagnet with interlayer coupling of individual ferromagnetic monolayers¹. This raises the possibility for new types of collective electronic quantum states that can be realized and manipulated^3,4. Due to its direct bandgap, CrSBr is optically active, and its magnetic properties can be probed through photoluminescence (PL) and optical absorption measurements². Here we report ultrafast time resolved PL measurements using streak camera on flakes of CrSBr with varying thickness at 77K. Thickness dependent PL lifetime is observed and attributed to different excitonic species and defect states.

 

References:

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Klein, J. et al. Sensing the local magnetic environment through optically active defects in a layered magnetic semiconductor. arXiv (2022) URL https://arxiv.org/abs/2207.02884v1

Lopez-paz, S.A. et al. Dynamic magnetic crossover at the origin of hidden order in van der Waals antiferromagnet CrSBr. Nature Communications (2022) URL https://www.nature.com/articles/s41467-022-32290-4#ref-CR28

Sierra, J.F. et al. Van der Waals heterostructures for spintronics and opto-spintronics. Nature Nanotechnology (2021) URL https://www.nature.com/articles/ s41565-021-00936-x