Optimization of textured-dielectric coatings for crystalline-silicon solar cells

We report on the optimization of textured-dielectric coatings for reflectance control in crystalline-silicon (c-Si) photovoltaic modules. Textured-dielectric coatings reduce encapsulated-cell reflectance by promoting optical confinement in the module encapsulation; i.e., the textured-dielectric coating randomizes the direction of rays reflected from the dielectric and from the c-Si cell so that many of these reflected rays experience total internal reflection at the glass-air interface. Some important results of this work include the following: we demonstrated textured-dielectric coatings (ZnO) deposited by a high-throughput low-cost deposition process; we identified factors important for achieving necessary texture dimensions; we achieved solar-weighted extrinsic reflectances as low as 6% for encapsulated c-Si wafers with optimized textured-ZnO coatings; and we demonstrated improvements in encapsulated cell performance of up to 0.5% absolute compared to encapsulated planar cells with single-layer antireflection coatings.