【Abstract】 We present a new deposition method of amorphous GaP films-Plasma Enhanced Chemical Transport Deposition (PECTD) and have successfully obtained a series of a-GaP films with a mirror-like surface and a stable chemical structure. The character of structure and composition ratio of a-GaP films have been investigated by XRD-spectra, IR absorption spectra and XPS. The results indicate that the stoichiometric composition of a-GaP films can be controlled by changing the deposition conditions such as the pressure in the deposition region, the temperature in the source region and the density of r.f. power.The optical properties of a-GaP films have been also studied systematically. The value of Egopt is aboat 1.6eV -which is greater than that reported by other group. We temporarily interpret this phenomenon by means of the existence of H and Cl atoms in a-GaP structure network. A long absorption band-tail in the energy band gap of a-GaP films was discovered.更多还原