Optical Absorption Spectra of Excitions in Very Thin KCl–KBr Multilayer Structures

Abstract

Optical absorption spectra of excitons in very thin alternating KCl–KBr multilayer structures are studied for the first time. Instead of KBr bulk-exciton peaks, new sharp spikes having a much steeper rise and located above the respective bulk-exciton peak are observed on these spectra. The spikes are interpreted with terms of quantum well exciton confined in the thin KBr layer. It is also suggested that mixture formed at inferfaces of the two materials plays important roles in the quantum confinements.