INCREASE IN THE DIFFUSION LENGTH OF CARRIERS IN POLYCRYSTALLINE PBTE FILMS

Polycrystalline lead chalcogenide films were investigated. These films differ from bulk single crystals in that they have a potential well w hich is formed by barriers at block boundaries. Implantation of zinc a nd oxygen in doses of 10(15)-10(17) cm-2 was used to form vertical p-n junctions in these films. The method of an electron-beam-induced curr ent was used to determine the diffusion length L of carriers. It was f ound that L increases compared with bulk single crystals. The increase in the diffusion length is attributable to an increase in the carrier lifetime because of the presence of a potential well, as confirmed ex perimentally.