Excition dynamics: intraband scattering and trapping in s-tetrachlorobenzene between 0·35 K and 1·25 K

Abstract

Time-resolved methods are used to study scattering and trapping processes in a one-dimensional triplet exciton system. Electron spin echo experiments indicate that intraband scattering in the lowest triplet exciton band t, in 1,2,4,5-tetrachlorobenzene is independent of chemical purity and certain forms of structural damage. Optical measurements between 0.35 K and 1.25 K demonstrate the importance of an 8 cm -1 trap at low temperature, and show further that trapping rates are independent of band state k for deep X-traps. The results suggest that the X-traps are not directly incorporated into the band structure of the host.

Spin-spin and spin-lattice relaxation in the triplet state ofAB-pairs in isotopically mixed crystals of naphthalene

“…To reach temperatures below 1"2 K we used a special 3He dewar which is inserted in a conventional r four-window cryostat. The details of this construction and its operation were described in [16].…”