Shpol’skii effect: new interpretation for the nature of the spectral multiplet structure and Bethe-splitting

Abstract

New approach to the interpretation of the multiplet structure in the Shpol’skii spectra based on the symmetry consideration of the impurity molecule and crystal matrix is proposed. The reasons and peculiarities of doublet structure formation in the spectra of molecules without inversion center and highly symmetric molecules are considered. It is shown that the structure of electron density distribution in the naphthalene molecule causes a doubly degenerate of the electronic level of its ground state. The calculated data are compared with the experimental results. The main research stages and directions in the field of narrow-line spectroscopy of organic molecules are marked.

Keywords:

• Impurity center
• Luminescence
• multiplet structure
• Shpol’skii effect
• symmetry

Disclosure statement

No potential conflict of interest was reported by the author(s)

Additional information

Funding

This work was supported by the grant of the National Research Foundation of Ukraine within the framework of the Project 2022.01/0011 "Innovative photonic technologies of bio-medical direction for the post-war reconstruction of Ukraine".