Anomalous characteristics of nanostructured hydrogenated carbon thin films

Hydrogenated diamond-like carbon (DLC) films are sought for several technological applications including electronics, optics, mechanics, and tribology. However, conventional hydrogenated DLC films, that commonly deposit at low base pressure (similar to 10(-5) to 10(-8) Torr), have many intrinsic limitations in terms of moderate hardness (15-25 GPa), low electrical conductivity (in insulating regime), and they display amorphous morphology. Here we develop high-performance hydrogenated carbon-based films using a cost-effective and fast deposition approach. We report the room temperature synthesis of nitrogen incorporated nanostructured hydrogenated carbon films (n-C:N:H) at a high base pressure of similar to 5 x 10(-3) Torr, employing a non-conventional radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) system equipped with only a primary pump. The n-C:N: H films show appealing properties such as wide band gap (2.35-2.9 eV), high optical transparency, high hardness (up to similar to 40 GPa), ultrahigh elasticity (elastic recovery similar to 95%), reasonably good electrical conductivity, and diode-like behavior when examined in n-C:N:H/Si heterojunction device configuration. Interestingly, some of nC:N:H films revealed the multifunctional activities with properties surpassing to those of many low base pressure grown traditional amorphous DLC films. This discovery solves many fundamental concerns of hydrogenated DLC films and opens new paths for their enhanced commercial applications.

Automated summary

The research team developed a new method for synthesizing nitrogen-doped nanostructured hydrogenated carbon films at high base pressure, which have wide applications and excellent performance. These films exhibit high hardness, transparency, electrical conductivity, and elastic recovery rate, showing superior electronic and optical properties.