Polarization-Field-Induced Inequivalent Exciton Dynamics in Janus MoSeS/MoSe2 Heterostructures

The interplay between excitons and physical fields emerges as a forefront research topic within the domain of condensed matter physics, harboring significant impact for unraveling material properties. Herein, we investigate the valley exciton behaviors in Janus MoSeS/MoSe₂ heterostructures with 2H- or 3R-stacking configurations. We ascertain that the intrinsic polarized electric field in Janus materials can markedly enhance the valley polarization. Furthermore, experimental results reveal that different excitons exhibit inequivalent spin-valley dynamic processes under intrinsic electric fields. Among them, intervalley trions exhibit a superior capability to preserve their spin states under a strong intrinsic electric field due to the quantum-confined Stark effect, thereby achieving the highest degree of valley polarization. This work provides fundamental insights into the strong correlation effect between excitons and polarized electric fields, signifying an advancement in control over the valley degree of freedom.