Selective enriching of trionic emission in a WS2-ZnO hybrid through type-II band alignment

Strategies to modulate the exciton dynamics in ultrathin two-dimensional (2D) semiconductors have always been an integral component in the bid towards improved optoelectronics and quantum photonic devices. The capability to non-destructively tune the relaxation dynamics, valley polarization, binding energies, and population ratio of various excitonic species has been well-sought for advanced applications. Through the rationale design of a WS 2 -ZnO hybrid platform, we present a distinct increment in the trion-to-exciton ratio for WS 2 emission across a patterned heterostructure. The shift in dominant excitonic species arose due to the efficient charge segregation at the spatially confined interface of the type-II heterostructure. Owing to the charge transfer process, the resultant emission profile presents up to four times amplification in the trion-to-exciton ratio, with temperature variable trion binding energies up to 59 meV. Since trions possess non-zero charge and spin degrees of freedom, the provision of a higher density of trions with increased binding stability would encourage new opportunities for reproducible optoelectronics and quantum emitters.