High Anti-Reflection Large-Scale Cup-Shaped Nano-Pillar Arrays via Thin Film Anodic Aluminum Oxide Replication

Surface anti-reflection (AR) with nanometer-scaled texture has shown excellent light trapping performance involving optical devices. In this work, we developed a simple and lithography-free structure replication process to obtain large scale surface cup-shaped nano-pillar (CSNP) arrays for the first time. A method of depositing was used for pattern transfer based on PMMA pre-coated through-hole anodic aluminum oxide (AAO) thin film (similar to 500 nm), and eventually, the uniformity of the transferred nanostructures was guaranteed. From the spectrum (250 nm similar to 2000 nm) dependent measurements, the CSNP nanostructured Si showed excellent AR performance when compared with that of the single-polished Si. Moreover, the CSNP was found to be polarization insensitive and less dependent on incidence angles (<= 80 degrees) over the whole spectrum. To further prove the excellent antireflective properties of the CSNP structure, thin film solar cell models were built and studied. The maximum value of J(ph) for CSNP solar cells shows obvious improvement comparing with that of the cylinder, cone and parabola structured ones. Specifically, in comparison with the optimized Si3N4 thin film solar cell, an increment of 54.64% has been achieved for the CSNP thin film solar cell.

Automated summary

This study developed a simple lithography-free process to obtain large-scale surface nano-pillar arrays with excellent anti-reflection performance. The CSNP nanostructured Si showed polarization insensitivity and low dependence on incident angles over the whole spectrum. Thin film solar cell models based on the CSNP structure showed significant improvement in efficiency compared to other structured ones.