Simulation, optimization, and characterization of AR surfaces for use with unique high-throughput fabrication techniques

Abstract

Optical anti-reflective (AR) surfaces are capable of improving performance of solar cells, HUD displays, and other important optical applications. However, fabricating these surfaces in a cost-effective way for large-area product applications has continued to be a challenge. In this paper we use rigorous coupled-wave (RCW) simulation to determine the effects fabrication constraints have on the performance of a sub-wavelength, anti-reflective pattern created with a new, highly scalable process. The goal is to use simulation results to drive meaningful improvements to the fabrication process, thereby broadening the applicability of AR surfaces. A number of possible AR surface geometries are simulated and analyzed, emphasizing the optimal geometries for low aspect ratios. The main parameters that dictate the efficiency and fabricability of AR surfaces are reviewed. Finally, we experimentally characterize a sample AR surface to validate the model and find the benefits and limitations of the new scalable fabrication process. RCW simulation indicates that the parabolic AR surface model is the best choice for our fabrication process, due to superior wide-angle reflectance reduction and ease of fabrication. Further analysis demonstrates that AR surfaces with higher fill factors and higher aspect ratios show noticeably lower reflectance. Experimental validation of a sample AR surface showed good conformity to simulation results, opening the door for further development of novel fabrication processes.