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Description
NiPS₃, a member of the metal phosphotrichalcogenide family, consists of crystalline layers strongly bonded within planes that are held together by weaker van der Waals forces. Quantum confinement effects promote the formation of tightly bound excitons, endowing NiPS₃ with properties of interest for applications in electrocatalysis and optoelectronic devices – such as transistors, photodetectors, and energy conversion systems – due to its tunable bandgap around 1.4 eV. Below its Néel temperature (150 K), the antiparallel alignment of nickel magnetic moments leads to antiferromagnetic ordering, opening opportunities for spintronic, magneto-optical, and magnetic storage applications, as well as for exploring two-dimensional magnetism. Notably, many-body phenomena such as collective excitonic states have also been observed below 150 K.
In this work, we employ time-resolved absorption spectroscopy (TAS) to investigate the ultrafast dynamics of charge carriers in NiPS₃. The transient response reveals a bimolecular relaxation process followed by a slower exponential decay, providing insights into carrier recombination pathways in this layered antiferromagnetic semiconductor. Temperature-dependent excitonic emission was also studied to gain insight into NiPS₃ photophysics.