Efficiency enhancement of silicon solar cells with silicon nanocrystals embedded in PECVD silicon nitride matrix

Anti reflection coatings (ARC), comprising of silicon-rich-nitride (SRN) films embedded with downconverting silicon nanocrystals were integrated into monocrystalline silicon solar cells fabricated using standard semiconductor fabrication techniques, and their effects were studied. Two types of ARC layers, one with single layer SRN film and other with double layer SiOx/SRN were deposited by plasma enhanced chemical vapor deposition (PECVD) during fabrication of silicon solar cells and thermally annealed to precipitate silicon nanocrystals. A relative increase in power conversion efficiency of 15.6% for single layer nanocrystals-embedded-ARC and 22.8% for double layer nanocrystals-embedded-ARC were observed compared to a reference cell.

► Efficiency enhancement in crystalline silicon solar cells with silicon nanocrystals (Si-nCs).
► The Si-nCs are synthesized inside PECVD silicon-rich-nitride ARC film.
► A 22.8% (2.9% absolute) relative increase in efficiency with optimized double layer ARC.
► Improvement attributed to downconverting silicon nanocrystals along with antireflection.