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Title: Charge-transfer-enhanced dd emission in antiferromagnetic NiPS 3
The d electron plays a significant role in determining and controlling the properties of magnetic materials. However, the d electron transitions, especially d– d emission, have rarely been observed in magnetic materials due to the forbidden selection rules. Here, we report an observation of d– d emission in antiferromagnetic nickel phosphorus trisulfides (NiPS 3 ) and its strong enhancement by stacking it with monolayer tungsten disulfide (WS 2 ). We attribute the observation of the strong d– d emission enhancement to the charge transfer between NiPS 3 and WS 2 in the type-I heterostructure. The d– d emission peak splits into two peaks, D 1 and D 2 , at low temperature below 150 K, from where an energy splitting due to the trigonal crystal field is measured as 105 meV. Moreover, we find that the d– d emissions in NiPS 3 are nonpolarized lights, showing no dependence on the zigzag antiferromagnetic configuration. These results reveal rich fundamental information on the electronic and optical properties of emerging van der Waals antiferromagnetic NiPS 3 .
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Applied Physics Reviews
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National Science Foundation
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