Abstract
Crystallography of CdS films evaporated in a vacuum was investigated. The results are as follows :
(1) The crystal structures of CdS films onto a cleaved NaCl crystal are dependent upon the substrate temperature and thickness of the CdS films. The critical temperature, at which the crystal structure of the CdS film of about 3000Å in thickness changes from hexagonal to cubic type, is about 340°C. Even in case of a higher substrate temperature than 340°C, a thinner CdS film has the hexagonal type, which changes from hexagonal to cubic type with increasing the film thickness.
(2) The crystal structure of a CdS film evaporated onto a noncrystalline carbon is a hexagonal type and the film is composed of fine crystal grains.
(3) Twin and dislocation were observed in both cubic and hexagonal CdS. The crystallographic relations between CdS films and NaCl (100) substrate are (100) Nacl// (100) CdS and <100>Nacl//<100>CdS for the cubic structure, (100) Nacl // (0001) CdS and <110>NaCl//<100>NaCl//<100>CdS for the cubic structure, (100) Nacl// (0001) Cds and <110>Nacl//<1100>CdS, and (100) Nacl // (0001) CdS and <110>Nacl//<1120>CdS for the hexagonal struc ture, the former is a epitaxial growth, and the latter is a textural growth.
(4) An activation energy of the grain growth of hexagonal CdS evaporated onto the noncrystalline carbon is 5.5 to 6.1 kcal/mol.
(5) Dislocation loops were observed in a nitrogen-ion implanted CdS film.
