A green, low-cost method to prepare GaN films by plasma enhanced chemical vapor deposition

In this study, the GaN films have been prepared by a green and low-cost plasma enhanced chemical vapor deposition (PECVD)method on Al2O3 substrate, along with Ga2O3 and N-2 as gallium source and nitrogen sources, respectively. The results show that the oxygen content in the GaN films is significantly influenced by the reaction temperature and N-2 flow rate. The uniform and high crystallinity GaN films were obtained at 950 degrees C with N-2 flow rate 150 sccm, which was also proved by high- resolution transmission electron microscopy (HRTEM) analysis. It is found that the high energy nitrogen plasma and additive graphite play vital role in the growth of the high-quality GaN films; and the graphite, used as reductive agent, avoided the unfavorable effect caused by the hydrogen radicals, thus, contributing to the GaN nucleation. Moreover, the photoresponsivity of the GaN film was observed to be 0.0125 A/W by 365 nm laser. Therefore, the GaN nanofilms prepared by the proposed green and low-cost PECVD method present a strong potential of application in photoelectric devices, such as ultraviolet photodetector, light emitting diodes and epitaxial substrate for the photoelectric materials.