Study of excitonic excited states in heterostructures with MoSe$_2$ monolayers

Heterostructures based on MoSe$_2$ monolayers were studied using the method of optical reflection spectroscopy, and the excited states of excitons were studied. It is shown that the shape of the reflection spectrum of the ground and excited states is determined by the thickness of the hexagonal boron nitride used in the heterostructure. Numerical modeling using the calculation of the reflectance of a heterostructure via the transfer matrix method gives a good agreement between the experimental line shape and the theoretical one, which confirms the universality of this method and makes it convenient for further research of van der Waals structures with other materials and parameters.