Biomimetic nanostructured antireflection coating and its application on crystalline silicon solar cells

J.Y Chen,K.W Sun,C.K Huang,W.-L Chang

doi:10.1364/oe.19.014411

Abstract

In this report, we demonstrate the implementation of biomimetic nanostructured antireflection coatings with polymethyl methacrylate (PMMA) layer on the micro-textured surface of silicon crystalline solar cells. To reduce cost, the process combines colloidal lithography, cast molding method, and reversal nanoimprint lithography. The technique is simple, low cost, and does not cause damage to the thin and brittle conventional crystalline solar cells. The antireflection properties of this biomimetic nanostructure coating are considered as effective as those of a conventional single-layer SiNx thin film. The resultant structures alone could reduce the average reflectance of solar cell from 13.2% to 7.8% and enhance power conversion efficiency from 12.85% to 14.2%.

Highlights

The performance of a solar cell is critically dependent on the absorption of incident photos and their conversion to current
Inasmuch as more than 30% of incident light is reflected from the silicon surface back to the air, an antireflection (AR) layer is a typical type of coating which can be applied to the surface to reduce light reflection and to increase light absorption
We demonstrate the implementation of a biomimetic nanostructure antireflection coating by combining reversal nanoimprint lithography, colloidal lithography, and cast molding method

Summary

Introduction

The performance of a solar cell is critically dependent on the absorption of incident photos and their conversion to current. The SWS can dramatically suppress the reflection and increase light transmission simultaneously at the interface, over a wide range of angles and wavelengths [6,7,8,9,10,11,12,13,14,15,16,17,18], because the surfaces have many tunable factors, such as period, depth, and cross-sectional geometry In addition to their high-performance optical properties, SWS arrays exhibit self-cleaning capability because of the high fraction of air trapped in the trough area between arrays [19]. Our biomimetic AR layer was demonstrated on conventional crystalline solar cells, and the overall AR effects were compared with a typical single-layer SiNx coating This combined technique provides a simple, scalable, and costeffective process to modify AR structures

Experiment process

Results and Discussion

Conclusion