Piezoreflectance of K⁺ 3p Core Excitons in KBr

Abstract

Effects of a uniaxial stress along the [011] direction on the K⁺ 3p core excitons in KBr are studied with the piezoreflectance technique. From stress dichroism, it is concluded that the core excitons located at 20.1 eV and 21.6 eV are due to the intraatomic transitions from the K⁺ 3p state to the 4s state and from the same state to the 3dγ state, respectively. Trigonal deformation potentials or these core excitons are determined and compared with that of the Γ exciton at the absorption edge.