Preparation of ZnS thin films by using photoassisted MOCVD

초록

Zinc sulfide thin films were grown by using both normal metal-organic chemical vapor deposition (MOCVD) and photoassisted MOCVD with diethylzinc and t-butylthiol as sources for the zinc and the sulfur, respectively. The effects of UV irradiation and reactor chamber pressure on the film growth were investigated. The basic physical properties of the ZnS thin films grown by using MOCVD were also investigated with X-ray diffraction, optical absorption, and Raman spectroscopy. The growth rate of the ZnS thin films grown by using photoassisted MOCVD were improved by about 28% compared to that of the films grown by using normal MOCVD. The growth rate also increased with increasing reactor chamber pressure. The energy band gap obtained from the optical absorption spectrum was 3.58 eV. MOCVD-grown ZnS thin films were hexagonal (lattice constants: a = 0.382 nm and c = 0.626 nm). In the Raman spectrum, the A(1) and the E-1 transverse peaks (A(1)(TO) and E-1(TO)) were observed at 277 cm(-1), and the A(1) and the E-1 longitudinal peaks (A(1)(LO) and E-1(LO)) were observed at 354 cm(-1).

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