A method for depositing a carbon-containing material layer onto a substrate includes delivering a mixture of precursors for the carbon-containing material layer into a process chamber, doping the carbon-containing material layer with silicon, and depositing the carbon-containing material layer at low temperature. In one aspect, improved light transmittance of the carbon-containing material layer at all wavelengths of a visible light spectrum is obtained. In addition, a method for depositing an encapsulating layer is provided for various display applications which require low temperature deposition process due to thermal instability of underlying materials used. The encapsulating layer may include one or more barrier layer material layers and one or more amorphous carbon material layers. The amorphous carbon material can be used to reduce thermal stress and prevent the deposited thin film from peeling off the substrate.