Effective Modulation of Interlayer Excitons in WSe2/WS2 Heterostructures by Plasmon–Exciton Interaction

Effective charge transfer and carrier separation at the interface are paramount for optimizing the performance of devices based on van der Waals heterostructures. In this investigation, surface plasmons generated by gold nanoparticles are employed to modulate the photocarrier dynamics in WSe2/WS2 heterostructures. The results of pump–probe measurements reveal that the efficiency of carrier transfer across the WSe2/WS2 heterostructure interface can be significantly enhanced via energy transfer mechanisms mediated by gold plasmons. Moreover, the electric field engendered by the plasmonic oscillations can modulate the dipole moment of the interlayer exciton. These well-aligned excitons avoid annihilation, and the extension of the lifetime of the excitons with increased pump power is realized by a screening effect. The findings presented herein offer valuable insights into the active manipulation of charge transfer and extend our understanding of the integral role played by plasmon–exciton coupling in mediating charge separation in van der Waals heterostructures.