Dynamical properties of the self-trapped exciton in AgCl as studied by time-resolved EPR at 95 GHz

A study is made of self-trapped excitons in AgCl using cw and pulsed EPR techniques at 95 GHz. This type of spectroscopy, owing to its superior resolution and its time-resolved character, allows us to obtain detailed information about the properties of these excitons. The singlet-triplet splitting is determined with great accuracy and the result confirms that the exchange interaction, present between the electron and the hole making up the exciton, is very small. From a measurement of the dynamic properties of the exciton in the triplet state it appears that a tunneling process takes place between the different Jahn-Teller distorted configurations of the (${\mathrm{AgCl}}_6$ ${)}^{4\mathrm{-}}$ complex at a rate of ${10}^5$ ${\mathrm{s}}^{\mathrm{-}1}$ at temperatures as low as 1.2 K.