AMORPHOUS DIAMOND-LIKE CARBON-FILMS - A HARD ANTI-REFLECTING COATING FOR SILICON SOLAR-CELLS

Amorphous diamond-line carbon (a:DLC) films are suitable for use as a protective layer and/or anti-reflecting coating for silicon solar cell s. Microhardness tests show a high hardness of about 4700 kg mm(-2) Op tical measurements in the visible light on a silicon solar cell withou t anti-reflecting coating where a:DLC was deposited as an anti-reflect ing (AR) coating, show a significant reduction in the reflection of th e light of about 25-45% as compared with the reflection from the solar cell before deposition of the a:DLC film. The current-voltage (I-V) c haracteristics of solar cells without an anti-reflecting coating and w ith a:DLC as the AR coating layer show an improvement in the short cir cuit current (from 107 mA to 116 mA) and in the efficiency of the cell by 1% (from 8% to 9%). I-V characteristics of a solar cell with AR co ating and deposited a:DLC (400 Angstrom thickness) over that film as a protective coating, show a slight reduction of the short circuit curr ent (from 168 mA to 145 mA), and the efficiency of the solar cell decr eases (16% to 14%). However, the microhardness was significantly incre ased.