Abstract
We demonstrate the effect of p-type dopant F4TCNQ molecular adsorption on the photoluminescence (PL) and valley polarization properties of trions in monolayer (1L) MoS2 at 15 K using a spatial PL mapping method. Trion PL intensity considerably increased after the treatment, which was attributed to the extended trion nonradiative lifetime (∼70 ps). Trion valley polarization as high as 0.75 showed a negligible decrease after the chemical treatment, as is the manifestation of a long trion valley lifetime of more than nanoseconds order. The results suggest that this method will be useful for future optovalleytronics applications of these materials.
Highlights
Trions, which are three-body charged excitonic bound states of electrons and holes, are expected to exhibit a much longer valley lifetime compared to excitons;30–32) they could potentially function as an alternative information carrier in optovalleytronics.30,31) trion emission is normally very weak and spatially heterogeneous, which prohibits the realistic application of trions in these materials
We found that the spatial uniformity of valley polarization of trions increased compared to the untreated samples, with the average trion valley polarization retained as high as 0.75 after the treatment
Rex, 1 + á ttr ñ / tv - tr where á ttrñ, tv - tr, and rx are effective trion lifetime, trion valley lifetime, and initially created exciton valley polarization, respectively.6,7,56) The Eq (1) suggests that á ttrñ and rtr are correlated in principle
Summary
Wenjin; Tanaka, Kenya; Hasegawa, Yusuke; Shinokita, Keisuke; Matsuda, Kazunari; Miyauchi, Yuhei.
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
