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A continuous wave (CW) Nd:YAG laser operating at the fundamental mode of 1.064pm was used to deposit CdS thin films with cubic phase on glass, quartz, NaC1 (100), and carbon coated formvar substrates. At substrate temperatures near 200°C, the films consisted of a combination of the zincblende (cubic) and wurtzite (hexagonal) phases of CdS. X-ray diffraction patterns of films deposited on each substrate indicate a predominantly cubic structure. Transmission electron microscopy further confirmed the presence of the cubic phase. The films had a stoichiometric ratio of 1:1 for Cd:S. The surface of the films were optically smooth. Optical transmission measurements reveal a room temperature absorption edge of 515 nm for the films deposited on glass and quartz substrates. Raman spectra show longitudinal optical (LO) modes at 300 cm1 (1LO) and 605 cm1 (2L0), similar to that of the hexagonal film. The transition from predominantly cubic to hexagonal films was estimated to occur near 275°C for glass substrates, and 350°C for quartz substrates.

There are two phases of CdS, wurtzite (hexagonal) and zincblende (cubic). To the best of our knowledge there is no report on the growth of large single crystal cubic CdS. Although there have been reports on the vapor deposition of cubic dominated CdS thin films, physical measurements were limited. Substrate material has been considered as the primary factor in attaining the cubic dominated CdS thin films. We report new results on CW Nd:YAG laser deposition of CdS thin films at various temperatures. X-ray diffraction patterns show that the films deposited at 200°C have a dominant cubic phase, those at 400°C being hexagonal. Optical transmission measurements reveal room temperature absorption edges of 515nm and 500nm for films deposited at 200°C and 400°C, respectively. Transmission electron microscopy further reveals differences in crystal structure of the two films. Raman spectra of the cubic film is similar to that of the hexagonal film.