In this work, the relaxation process in mixtures of a nematic liquid crystal matrix with additives of azochromophores and CdSe/ZnS quantum dots is analyzed. The thermally initiated mesophase—isotropic liquid phase transition showed that the activation energy of this process increases almost equally upon the addition of AX-7 or AX-8 in an amount of 10 wt %. However, the photoinduced phase transition into isotropic state, analyzed by dielectric spectroscopy, demonstrates a significant difference when different azochromophores are present in the system as confirmed by activation energy values. This effect is associated with changes in the ratio of trans–cis-isomers. IR-spectroscopy revealed the unexpecting predominance of cis-isomers in AX-7, while trans-isomers are typical for AX-8. This difference was explained by a change in the distribution of electron density in the azochromophore fragments, taking into account the influence of aromatic ring substituents.