Characteristics of Diamond-Like Carbon Thin Film Semiconductor for Photovoltaic Application

Abstract

Diamond-Like Carbon (DLC) thin film semiconductors were produced by Radio Frequency Plasma Enhanced Chemical Vapour Deposition (RF-PECVD) method and characterized by nanoindentation to investigate its mechanical properties for protective coating applications. The XRD analysis showed that the films were hydrogenated amorphous carbon (a-C:H) nature. The thickness of the films was measured by Ellipsometry and Profilometry. The thickness variation with deposition rate followed a linear relationship within the various deposition parameters showed a good homogeneity formed of DLC films. The hardness value linearly varied with RF power at 30 mTorr showed an optimum pressure to form a quality DLC thin film. The optimum RF power and CM pressure was 150 watt and 30 mTorr showed the thin film hardness 18.73 ± 2.51 GPa and reduced modulus 171.04 ± 11.13 GPa and the films were investigated as hard hydrogenated amorphous carbon (a-C:H) structure. The high hardness value and the deposition parameters showed that the deposition method of RF-PECVD was a controlled deposition process especially for a-C:H DLC thin film deposition. The thickness effects on hardness of the film implied that the optimum deposition condition was an important aspect to get quality DLC films for protective coating application.