Modeling Interlayer Exciton Trapping in Two-dimensional Heterostructures with Discrete, Random-walks

Excitons in transition metal dichalcogenides (TMDCs) host a wealth of many-body physics and exciting applications in photonic and optoelectronic devices. Local strain modulation in TMDCs creates potential traps which localize excitons. These strain-induced traps can localize interlayer excitons (IXs) in TMDC vertical heterostructures.[1,2] Trapped IXs in TMDCs are ideal candidates for condensate formation and long-wavelength single photon emitters.[3] Using a discrete, random-walk model, we simulate trapping of IXs in traps of varying depth, density, and shape to explore the experimentally relevant parameter space for efficient trapping of IXs. Our results show that dipole-dipole interactions between IXs play an important role in regulating IX trapping. The effects of these dipole interactions are mitigated with many small, deep traps which are synthetically possible using defects and moiré potentials.

References:
1] Kremser et al. npj 2D Mater. Appl. 4, 8 (2020)
2] Wang et al. ACS Photon. 7, 2460 (2020).
3] Yu et al. Sci. Adv. 3, e1701696 (2017)