Study on the Size and Shape of CuCl Microcrystals Embedded in Alkali‐Chloride Matrices and Their Correlation with Exciton Confinement

In alkali chlorides heavily doped with Cu + ions, CuCl microcrystals of different sizes are grown under different heat treatments. Their size and shape are studied using small‐angle X‐ray scattering. A clear correlation is established between the microcrystal size and the blue shift of the exciton luminescence peak. The quantum size effect on the exciton is discussed. The exciton confinement, that is, the restriction of the exciton translational motion in one‐dimensional quantum wells is found to be rather plausible for CuCl microcrystals in crystalline matrices.