Observation of optical transition energy in ZnSe/tris(8-hydroxyquinoline) aluminum (Alq3)/ZnSe single quantum wells by photoreflectance spectroscopy

Abstract

The optical transition energy in ZnSe/tris(8-hydroxyquinoline) aluminum (Alq3)/ZnSe single quantum wells (SQW) thin films with well thickness from 5 to 50 nm was investigated by room-temperature photoreflectance (PR) measurements. PR features due to optical transition energy were observed in the SQWs of well thicknesses. The transition energies were determined by fitting the PR spectra to the theoretical line-shape expression. The transition energy decreased with increasing well thickness.