Interference of resonance luminescence of exciton polaritons in CuGaS2 crystals

Abstract

Excitons spectra in crystals CuGaS2 are investigated, in which the basic and excited states of excitons Γ4 and Г5 are found. The resonant luminescence ant its interference is found in the range excited states of excitons Γ4 and Г5. Interference in the luminescence spectra is observed in the samples of the thickness 0,5-1,5 μm. At excitation by the line 4765 Å of the Ar+laser the radiation bands are not practically found, their intensity is very weak. The observed radiation possesses a resonance character, because the excitation energy of 2,5402eV is close to the lines п = 2 of the exciton Г4. In the luminescence spectra another peculiarity is observed too. The intensity of the interference bands decreases as the wavelength increases relative to the central band of radiation of 2,5307 eV.