Low cost CBD ZnS antireflection coating on large area commercial mono-crystalline silicon solar cells

Zinc sulfide is a wide band gap semiconductor with high refractive index and hence a promising material for antireflection coating over commercial silicon solar cells. In the present work, attempts have been made to improve the rate of deposition, uniformity of deposited film, stoichiometry, refractive index and the percentage of reflection, respectively, by proper optimization of molar percentage of different CBD ZnS bath chemical constituents and deposition conditions. High values of the rate of film deposition (19.6 Å), film uniformity (S.D.<1.8) and refractive index (2.35) along with a low percentage of average reflection (0.655) are achieved with proper optimization of ZnS bath. We have successfully fabricated 13.8% efficient large area (103 mm×103 mm) mono-crystalline silicon solar cells with CBD ZnS antireflection coating.     

Broadband antireflective structures with hole for highly transparent glasses

Optimal sub-wavelength structures (SWS) with parabolic hole on glass substrate are designed using effective medium theory (EMT), which will reduce the reflectance over wavelength range from 300 to 1200 nm and 0° to 80° angle of incidence. The performance of SWS integrated glass is verified by genetic algorithm. The optimized SWS with the cross-sectional profile of parabolic hole have parameters with ∼120 nm diameter and 300 nm height. The average reflectance over wavelength range from 300 to 1200 nm and 0° to 80° angle of incidence could be reduced to only 0.5% by applying the optimized SWS onto glass.     

Heat-insulation film with gold layer deposited on antireflection subwavelength-structured surface

The optical properties of gold layer deposited on antireflection subwavelength-structured surface are first exposed. The experimental results of the reflectances and transmittances for several different thicknesses of gold-deposited layers on the subwavelength structures are carried out. The nanostructured surface with spatial period and a diameter of about 230 nm and height of about 150 nm on polyethylene terphthalate (PET) film is fabricated by micro-replication process of UV imprinting. Comparing these with the bare gold-deposited layer and bare nanostructure, the results show that the optical films with the suitable gold layer deposited on antireflection subwavelength-structured surface has high transmittance and low glare in the visible spectral range and high reflectance in the infrared range. That is to say, when the antireflection subwavelength-structured surface is coated with a gold layer of several tens of nm thickness, it will have some unique optical characters.     

Imperfect antireflection coating effect reduction schemes for birefringent interleaver and optical communication systems

Chromatic dispersion (CD) caused by an imperfect antireflection coating is a great concern for optical engineers, and different techniques have been proposed to reduce CD in optical devices. In this article, we investigate two popular CD reduction techniques used in birefringent interleaver manufacturing and their effects on performance improvement of optical communication systems. Our results show that some CD reduction scheme bringing about a smaller CD ripple amplitude does not necessarily guarantee better system performance. This result can be used as a guideline for optical engineers working on reducing CD caused by an imperfect antireflection coating.