Optimization of surface reflectance for silicon solar cells

Gagik Ayvazyan,Sergey Minasyan,Razmik Barseghyan,N Voropai,G Chang,F.-J Lin,A Kler,R Lis

doi:10.1051/e3sconf/20186901008

Gagik Ayvazyan, Sergey Minasyan + Show 6 more

Open Access

https://doi.org/10.1051/e3sconf/20186901008

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Abstract

A study on the formation of black silicon (b-Si) antireflection layers on crystalline Si wafers using SF6/O2gas mixture in a reactive ion etching method is presented. The process is low-temperature, fast and does not depend on the crystallographic orientation of the Si wafer. The b-Si layers have demonstrated average reflectance values of 4% and 5% for monoand polycrystalline Si wafers respectively, feature that is suitable for the fabrication of high efficiency solar cells. Passivation of b-Si antireflection layers by suitable different thin films can significantly reduce needle-like surface recombination losses.

Highlights

Silicon (Si) with various structural morphologies is widely used for solar cells and other electro-optical devices
The minimization of reflection losses is of crucial importance for high efficiency Si solar cells, and a variety of approaches has been developed to this end, in many cases specific to a particular surface morphology [1]
The morphology of the black silicon (b-Si) was observed by scanning electron microscope (SEM)

Summary

Introduction

Silicon (Si) with various structural morphologies is widely used for solar cells and other electro-optical devices. Photolithography-free wet chemical texturing processes have been used in order to produce pyramid-like structures in the Si surface [2,3,4]. The unusual photoelectric characteristics, combined with the semiconducting properties of silicon make b-Si interesting for solar cells applications as antireflection layers [7,8,9]. These nanostructures as antireflection layer increase the surface area of the solar cells, and increase the amount of sunlight that is captured rather than reflected back from the cells (Fig.). Modifying the material in this way makes it a lot less reflective, allowing solar cells that use it to trap light even when it's coming from very low angles

Solar cells fabrication

Results and discussion

Conclusions