We report on the far-field photoluminescence intensity distribution of interlayer excitons in MoSe2-WSe2 heterostacks as measured by back focal plane imaging in the temperature range between 1.7 K and 20 K. By comparing the data with an analytical model describing the dipolar emission pattern in a dielectric environment, we are able to obtain the relative contributions of the in- and out-of-plane transition dipole moments associated to the interlayer exciton photon emission. We determine the transition dipole moments for all observed interlayer exciton transitions to be (99 ± 1)% in-plane for R- and H-type stacking, independent of the excitation power and therefore the density of the exciton ensemble in the experimentally examined range. Finally, we discuss the limitations of the presented measurement technique to observe correlation effects in exciton ensembles.
@article{arxiv.2111.01886,
title = {Optical dipole orientation of interlayer excitons in MoSe$_{2}$-WSe$_{2}$ heterostacks},
author = {Lukas Sigl and Mirco Troue and Manuel Katzer and Malte Selig and Florian Sigger and Jonas Kiemle and Mauro Brotons-Gisbert and Kenji Watanabe and Takashi Taniguchi and Brian D. Gerardot and Andreas Knorr and Ursula Wurstbauer and Alexander W. Holleitner},
journal= {arXiv preprint arXiv:2111.01886},
year = {2022}
}