Enhancing Single-Layer WSe2 Light Emission in Perylene-Doped Polymer Films through Efficient Energy Transfer

The optical and mechanical properties of 2D semiconductors make them excellent candidates for the active components of plastic optoelectronic devices. Here, the integration of single-layer WSe2 (1L-WSe2) into a polystyrene (PS) film containing dispersed perylene orange (PDI-O) molecules is investigated. The findings reveal a notable enhancement in the light emission of 1L-WSe2, which occurs exclusively upon PDI-O excitation and scales with the concentration of molecules in the PS film. Moreover, the increase in 1L-WSe2 photoluminescence coincides with a quenching of the PDI-O light emission intensity and a decrease in its lifetime. These results point to efficient long-range interactions, such as Förster energy transfer, between PDI-O (acting as the donor) and 1L-WSe2 (acting as the acceptor), as the mechanism responsible for the enhanced light emission in the latter. These findings are of great interest for the development of flexible optoelectronic devices integrating active 2D materials; the polymeric matrix plays a dual role, serving as both physical support and host for organic dopants that can optimize the light emission properties of the active 2D material.