Diamond-like carbon protective anti-reflection coating for Si solar cell

Diamond-like carbon (DLC) films were deposited on corning glass and silicon substrates by the RF-PECVD (Plasma Enhanced Chemical Vapor Deposition) method using methane (CH4) and hydrogen (H2) gases. We examined the effects of the CH4 to H2 ratio on the tribological and optical properties of the DLC films. The hardness of the DLC films was measured with a nano-indenter. The optical properties of the DLC thin film were investigated by UV/VIS spectrometry and ellipsometry. From these measurements, we obtained optimum anti-reflection coating at a methane flow rate of 20 sccm. Also, solar cells were fabricated on a silicon substrate using the optimized DLC films as an anti-reflection coating and we obtained an increase of solar cell efficiency of about 20%.