Luminescence of CuCl Crystal and Its Correlation to the Exciton–I

Very narrow lines and abroad band have been observed in emission with the excitation into the band to band region or the exciton absorption band. Narrow emissions consist of a strong 3901 Å, a weak 3870 Å and a very weak 3785 Å lines at 4°K. They are attributed to the n =1 Stokes, n =1 and n '=1 resonance exciton emissions, respectively. n =1 and n '=1 are the first members of the sharp and the diffuse absorption line-series. A broad emission consists of two bands peaking at 4030 and 4250 Å. The former emission band has an asymmetric shape and is ascribed to the annihilation of a trapped exciton. From the temperature dependence of the emission intensity and the photoconductivity, the discussion is given on the emission processes.