Antonio Rossi1,Jonas Zipfel1,Emma Regan2,Daria Blach3,1,Luca Francaviglia1,Monica Lorenzon1,Edward Barnard1,Eli Rotenberg1,Feng Wang2,Archana Raja1,Alexander Weber-Bargioni1
Lawrence Berkeley National Laboratory1,University of California, Berkeley2,Purdue University3
Antonio Rossi1,Jonas Zipfel1,Emma Regan2,Daria Blach3,1,Luca Francaviglia1,Monica Lorenzon1,Edward Barnard1,Eli Rotenberg1,Feng Wang2,Archana Raja1,Alexander Weber-Bargioni1
Lawrence Berkeley National Laboratory1,University of California, Berkeley2,Purdue University3
The moiré potential arising from the relative twist and lattice mismatch in heterobilayers of two-dimensional materials has led to the discovery of novel excitonic species. Twist-angle dependent transport measurements of these interlayer excitons have been reported for WSe2/WS2 heterobilayers [1]. In our experiment, we use time- and spatially resolved spectroscopies to investigate the temperature dependent lifetime and diffusion length of various interlayer excitons in WSe2/WS2 heterobilayers, where the individual monolayers have been aligned to produce long-range moiré superlattices. We observe that the interlayer exciton diffusion length increases with temperature till it undergoes a phonon-driven transition where the intralayer exciton starts to dominate the photoluminescence spectrum. The temperature dependent formation of the interlayer exciton is reflected in the overall lifetime and diffusion lengths of exciton species in the WSe2/WS2 heterobilayer.<br/>[1] Yuan, Long, et al. <i>Nature materials</i> 19.6 (2020): 617-623