EXCITONIC PHOTOCONDUCTIVITY IN PLASTICALLY DEFORMED CUPROUS-OXIDE

The authors begin with a short review of the properties of the optical quadrupolar transition towards the 1S excitonic state of Cu//2O, in the perfect crystal as well as in the crystal perturbed by an electric field and report recent results about plastic properties of Cu//2O crystals. The deformed crystals present a strong anisotropy of the photocurrent in the 1S excitonic line. An optical scanning allows a point by point measurement of the photocurrent. It shows that the anisotropy is related to the particular ordering of dislocations in walls. The dissociation mechanism of excitons in free carriers in the vicinity of dislocations is established.