RELATION BETWEEN DISLOCATION DENSITY, BULK ELECTRICAL-PROPERTIES AND OHMIC CONTACTS OF CDTE

There are large variations in the density and distribution of dislocations in CdTe crystals. The dislocation density was determined by etching. For the electrical measurements (Hall effect and conductivity by the Van der Pauw method), crystal regions were selected which showed extremely different dislocation densities. The dislocation density did not noticeably affect the bulk electrical properties. For the preparation of ohmic contacts, a thin, strongly disturbed surface region with a high dislocation density appears to be necessary. On crystal disks with low as-grown dislocation densities, dislocations were produced by lapping or other mechanical treatment to prepare ohmic contacts on high-resistivity CdTe for Hall effect measurements.