Contribution of Excitons to the Optical Properties of GaSe

Abstract

AbstractFaraday effect measurements were performed on excitons in GaSe using a pulsed magnetic field up to 80 kG in synchronous operation. The interpretation of the experimental data showed the necessity of Zeeman splitting, magnetoabsorption and dichroism measurements. The analysis of the results suggested an analytical model taking into account the contribution of excitons to the optical constants of GaSe. Using this model the experimental data were successfully fitted. Such an approach is quite general and can be used every time one has well isolated resonances for which Nƒ ≪ (ϵ0 μ γ ω0)/(2 π e2). It is shown that this condition is satisfied for GaSe, for Nƒ = 1.06 × 1017 cm−3, g+ = −3.5 is obtained while the damping factor γ changes from sample to sample between 3.6 × 1012 and 4.5 × 1012 s−1.